This document discusses questions related to pure substances and mixtures. It provides answers to questions about classifying mixtures as homogeneous or heterogeneous, identifying solutions, distinguishing between physical and chemical changes, and techniques for separating mixtures like distillation, crystallization, chromatography, and centrifugation. Key topics covered include properties of pure substances and mixtures, types of mixtures, solubility and saturation, and separation methods for mixtures and solutions.
Chemistry is the study of substances and their composition, structure, properties, and reactions. Chemical reactions occur all around us in many everyday processes from starting a car to digesting food. Organic chemistry is the study of carbon compounds, which are found in materials like plastics and polymers as well as living things like DNA and foods. Chemical and physical changes can be distinguished based on whether the identity of a substance changes, with chemical changes occurring at the molecular level to form new substances. Acids and bases are found throughout the body and in many other natural and industrial processes.
This document provides information about acids, bases, salts, and pH scale. It defines acids and bases, describes their properties and classifications. It discusses the preparation and uses of acids, bases, and salts. It also explains what the pH scale measures, how it indicates acidity and basicity, and how pH values correspond to acids and bases.
Matter is anything that has mass and occupies space. There are three main types of matter based on physical state: solids, liquids, and gases. Matter can also be classified as pure substances or mixtures.
A pure substance contains only one type of atom or molecule and has uniform composition and predictable properties like melting/boiling points. Elements are pure substances made of only one type of atom, while compounds are made of two or more elements chemically bonded together. Mixtures contain two or more substances mixed but not chemically combined, and can be either homogeneous like solutions, or heterogeneous like suspensions.
The document then discusses various pure substances and mixtures in more detail, including their properties and examples. It also explains
This document discusses a science presentation about the properties and reactions of metals and non-metals. It lists the group members giving the presentation and describes several properties of metals like malleability and conductivity. It then discusses how metals react with oxygen, water, acids, salt solutions, chlorine, hydrogen and how alloys are formed and used. For non-metals, it summarizes their reactions with oxygen, water, acids, salt solutions, chlorine, hydrogen and describes ionic compounds.
Matter can be classified as pure substances or mixtures. Pure substances are either elements or compounds, while mixtures can be homogeneous or heterogeneous. Solutions are homogeneous mixtures where one substance dissolves evenly throughout another. There are several processes that can separate mixtures into their component substances, such as evaporation, crystallization, centrifugation, chromatography, and distillation. Physical changes alter the state of matter but do not change its chemical makeup, while chemical changes form new substances through chemical reactions.
Is matter around us pure- Chapter 2 class10 NCERTRAVNEET NAGI
1. The document discusses different types of matter including pure substances and mixtures. Pure substances are either elements or compounds, while mixtures contain two or more substances mixed together.
2. Mixtures can be separated into their components using physical methods, while pure substances require chemical methods to separate. Common techniques to separate mixtures include evaporation, filtration, centrifugation, and distillation.
3. Solutions, suspensions, and colloids are described as types of homogeneous and heterogeneous mixtures. The properties and differences between these mixtures are outlined.
The document discusses the reaction of various metals with acids. When metals like magnesium, aluminum, zinc, and iron react with hydrochloric acid, they produce bubbles of hydrogen gas. Copper does not react with dilute hydrochloric acid and produces no bubbles. Unlike reactions with hydrochloric acid, reactions of metals with nitric acid do not produce hydrogen gas. Aluminum also does not react with nitric acid due to the formation of a protective layer of aluminum oxide.
This document provides an overview of matter and its properties. It discusses the following key points:
1) Matter is anything that occupies space and has mass. It can be classified based on physical state (solid, liquid, gas), chemical composition (pure substances and mixtures), and early Indian philosophical elements.
2) Matter is made of very tiny particles that are in continuous motion, have space between them, and attract each other. The three states of matter are solids, liquids, and gases, which differ in properties like compressibility and particle movement.
3) Changes of state, such as melting, boiling, sublimation, and evaporation occur when heat is added or removed and cause phase transitions between
Chemistry is the study of substances and their composition, structure, properties, and reactions. Chemical reactions occur all around us in many everyday processes from starting a car to digesting food. Organic chemistry is the study of carbon compounds, which are found in materials like plastics and polymers as well as living things like DNA and foods. Chemical and physical changes can be distinguished based on whether the identity of a substance changes, with chemical changes occurring at the molecular level to form new substances. Acids and bases are found throughout the body and in many other natural and industrial processes.
This document provides information about acids, bases, salts, and pH scale. It defines acids and bases, describes their properties and classifications. It discusses the preparation and uses of acids, bases, and salts. It also explains what the pH scale measures, how it indicates acidity and basicity, and how pH values correspond to acids and bases.
Matter is anything that has mass and occupies space. There are three main types of matter based on physical state: solids, liquids, and gases. Matter can also be classified as pure substances or mixtures.
A pure substance contains only one type of atom or molecule and has uniform composition and predictable properties like melting/boiling points. Elements are pure substances made of only one type of atom, while compounds are made of two or more elements chemically bonded together. Mixtures contain two or more substances mixed but not chemically combined, and can be either homogeneous like solutions, or heterogeneous like suspensions.
The document then discusses various pure substances and mixtures in more detail, including their properties and examples. It also explains
This document discusses a science presentation about the properties and reactions of metals and non-metals. It lists the group members giving the presentation and describes several properties of metals like malleability and conductivity. It then discusses how metals react with oxygen, water, acids, salt solutions, chlorine, hydrogen and how alloys are formed and used. For non-metals, it summarizes their reactions with oxygen, water, acids, salt solutions, chlorine, hydrogen and describes ionic compounds.
Matter can be classified as pure substances or mixtures. Pure substances are either elements or compounds, while mixtures can be homogeneous or heterogeneous. Solutions are homogeneous mixtures where one substance dissolves evenly throughout another. There are several processes that can separate mixtures into their component substances, such as evaporation, crystallization, centrifugation, chromatography, and distillation. Physical changes alter the state of matter but do not change its chemical makeup, while chemical changes form new substances through chemical reactions.
Is matter around us pure- Chapter 2 class10 NCERTRAVNEET NAGI
1. The document discusses different types of matter including pure substances and mixtures. Pure substances are either elements or compounds, while mixtures contain two or more substances mixed together.
2. Mixtures can be separated into their components using physical methods, while pure substances require chemical methods to separate. Common techniques to separate mixtures include evaporation, filtration, centrifugation, and distillation.
3. Solutions, suspensions, and colloids are described as types of homogeneous and heterogeneous mixtures. The properties and differences between these mixtures are outlined.
The document discusses the reaction of various metals with acids. When metals like magnesium, aluminum, zinc, and iron react with hydrochloric acid, they produce bubbles of hydrogen gas. Copper does not react with dilute hydrochloric acid and produces no bubbles. Unlike reactions with hydrochloric acid, reactions of metals with nitric acid do not produce hydrogen gas. Aluminum also does not react with nitric acid due to the formation of a protective layer of aluminum oxide.
This document provides an overview of matter and its properties. It discusses the following key points:
1) Matter is anything that occupies space and has mass. It can be classified based on physical state (solid, liquid, gas), chemical composition (pure substances and mixtures), and early Indian philosophical elements.
2) Matter is made of very tiny particles that are in continuous motion, have space between them, and attract each other. The three states of matter are solids, liquids, and gases, which differ in properties like compressibility and particle movement.
3) Changes of state, such as melting, boiling, sublimation, and evaporation occur when heat is added or removed and cause phase transitions between
This document provides information about the structure of the atom. It discusses the three main subatomic particles - electrons, protons, and neutrons. It describes the discoveries of these particles by scientists like Thomson, Goldstein, and Chadwick. The document then explains four major atomic models - Thomson's model, Rutherford's model, Bohr's model, and the distribution of electrons in shells. It also discusses concepts like atomic number, mass number, isotopes, isobars, and valency.
This document outlines key concepts about acids, bases, and salts. It defines acids as substances that produce hydrogen ions in water. There are strong acids that fully ionize and weak acids that partially ionize. Bases are oxides or hydroxides of metals. Alkalis are soluble bases that produce hydroxide ions in water. Acids and bases react to form salts and water in a neutralization reaction. The pH scale measures acidity and alkalinity. Indicators change color with pH. There are four types of oxides. Salts contain cations from bases and anions from acids. Common salts have various industrial and domestic uses.
The document defines acids as substances that dissociate in water to produce hydrogen ions, and describes some of their key properties, such as sour taste and turning litmus red. It also discusses important acids like hydrochloric acid and sulfuric acid, and their common uses. Similarly, bases are defined as substances that dissociate to produce hydroxide ions in water. Important bases and their uses are also outlined, along with definitions and examples of salts.
The document discusses metals and non-metals. It describes the physical and chemical properties of metals and non-metals. Metals are lustrous, malleable, ductile and are good conductors of heat and electricity, while non-metals have opposite properties. It also discusses how metals and non-metals react with oxygen, water, acids and how displacement reactions can be used to determine reactivity order. Metals are extracted from ores through processes like enrichment, extraction using chemical/electrochemical methods depending on their reactivity.
This document discusses the properties and states of matter. It defines matter as anything that takes up space and has mass. Physical properties are characteristics that can be observed or measured without changing the substance, such as mass, volume, density, and state of matter (solid, liquid, gas). A mixture is a combination of two or more substances that keep their own properties, while a solution is a type of mixture where particles are evenly mixed but not easy to separate. The state that matter exists in depends on temperature and pressure - it can change states between solid, liquid and gas through physical processes like melting, freezing, boiling, evaporation and condensation that involve adding or removing heat.
Chapter 3.metals and non metals priya jhaPriya Jha
An element is the simplest form of matter that cannot be split into simpler substances or built from simpler substances by any ordinary chemical or physical method. There are 118 elements known to us, out of which 92 are naturally occurring, while the rest have been prepared artificially. Elements are further classified into metals, non-metals, and metalloids based on their properties, which are correlated with their placement in the periodic table.Metals
With the exception of hydrogen, all elements that form positive ions by losing electrons during chemical reactions are called metals. Thus metals are electropositive elements with relatively low ionization energies. They are characterized by bright luster, hardness, ability to resonate sound and are excellent conductors of heat and electricity. Metals are solids under normal conditions except for Mercury.Nonmetals
Elements that tend to gain electrons to form anions during chemical reactions are called non-metals. These are electronegative elements with high ionization energies. They are non-lustrous, brittle and poor conductors of heat and electricity (except graphite). Non-metals can be gases, liquids or solids.Metalloids
Metalloids have properties intermediate between the metals and nonmetals. Metalloids are useful in the semiconductor industry. Metalloids are all solid at room temperature. They can form alloys with other metals. Some metalloids, such as silicon and germanium, can act as electrical conductors under the right conditions, thus they are called semiconductors. Silicon for example appears lustrous, but is not malleable nor ductile (it is brittle - a characteristic of some nonmetals). It is a much poorer conductor of heat and electricity than the metals. The physical properties of metalloids tend to be metallic, but their chemical properties tend to be non-metallic. The oxidation number of an element in this group can range from +5 to -2, depending on the group in which it is located.
Ncert class 10 - science - chapter 3 - metals and non-metalsEswariKumaravel
The document discusses the properties of metals and non-metals. It describes how metals are lustrous, malleable, ductile, and good conductors of heat and electricity, while non-metals lack these properties. Experiments are presented to demonstrate that metals are lustrous, hard except for a few, malleable by hammering into thin sheets, and ductile by pulling into wires. Other experiments show that metals conduct heat by melting wax and conduct electricity by lighting a bulb. The document contrasts how metals and non-metals react with oxygen, water, acids, and how metals react in salt solutions in displacement reactions.
The document provides information about various chemistry concepts related to air and water:
- It describes chemical tests to identify water and the purification of water supplies through filtration and chlorination.
- The composition of clean air is described as 78% nitrogen, 21% oxygen and small quantities of other gases. Common air pollutants like carbon monoxide and their sources are stated.
- Fractional distillation is outlined as the process used to separate oxygen and nitrogen from liquid air based on their different boiling points.
- Rusting is described as a reaction between iron, air and water that can be prevented by methods like painting and galvanizing to exclude oxygen.
The document discusses acids and bases, including their properties, examples of common acids and bases, and how strong vs. weak acids and bases are classified. Acids are sour, turn litmus red, and contain hydrogen ions. Bases are slippery, turn litmus blue, and contain hydroxide ions. Strong acids and bases have more hydrogen or hydroxide ions respectively and can be caustic.
This document discusses different types of matter and mixtures. It defines pure substances as being made of a single type of matter, either an element or compound. Mixtures contain two or more substances mixed together physically. Pure substances are classified as elements, which cannot be broken down further, or compounds, which contain two or more elements chemically bonded. Mixtures include homogeneous mixtures, where the composition is uniform, and heterogeneous mixtures where it is not. The properties and examples of each type of pure substance and mixture are described.
This document provides an overview of chemical reactions and equations. It discusses chemical changes and how they can be represented by balanced chemical equations. The main types of chemical reactions covered are combination reactions, decomposition reactions, displacement reactions, and oxidation-reduction reactions. Examples of each type of reaction are given. The document also explains how to balance chemical equations by ensuring equal numbers of each type of atom on both sides of the reaction equation.
This document provides an overview of metals and non-metals. It discusses their physical and chemical properties, including how metals react with oxygen, water, acids, and other substances. Metals are solid, malleable, ductile, and good conductors of heat and electricity. They form basic oxides and react vigorously with acids. Non-metals do not have these properties and are usually gases or solids. The document also covers extraction methods for metals and corrosion prevention.
This document discusses types of chemical reactions, including:
1) Combination reactions where two or more reactants combine to form products, such as magnesium combining with oxygen to form magnesium oxide.
2) Displacement reactions which can be metal-metal, where a more reactive metal displaces a less reactive one, or metal-nonmetal where a metal displaces a nonmetal.
3) The document provides examples of combination and displacement reactions and classifies common types of chemical reactions like decomposition, double displacement, and oxidation-reduction reactions.
This document discusses the classification and properties of pure substances and mixtures. It defines pure substances as elements or compounds that consist of a single type of matter, while mixtures contain two or more pure substances mixed together. Mixtures are classified as either homogeneous, containing substances mixed uniformly, or heterogeneous, containing visible particles that can be separated. The document also discusses various techniques for separating components of mixtures like evaporation, centrifugation, distillation and crystallization.
Chemical reactions and equations class 10 CBSEritik
This document discusses chemical reactions and equations. It defines a chemical reaction as a process where reactants are converted into products, which may occur under the influence of a catalyst. It describes how to write chemical equations and balance them by ensuring equal numbers of each type of atom on both sides of the reaction. It also defines and provides examples of different types of chemical reactions: combination, decomposition, displacement, double displacement, and redox reactions. Corrosion and rancidity are discussed as examples of oxidation reactions.
This document discusses various techniques for purifying substances, including filtration, crystallization, distillation, and chromatography. It provides examples of how each technique works and the types of mixtures it can be used to separate. Key points include:
- Filtration separates insoluble solids from liquids by passing the mixture through a filter paper.
- Crystallization forms pure crystals of a soluble solid by slowly evaporating the solvent from a saturated solution.
- Distillation boils a liquid mixture and condenses the vapor to separate components with different boiling points.
- Chromatography separates mixtures by exploiting differences in how substances partition between a stationary and mobile phase.
hello friends this is dattatreya and team.so we all did research on the 2nd chapter of chemistry that is "is matter around us pure so hope you like it and please download it....
Topics Included
• Introduction
• Metals
→ Physical properties of metals
→ Chemical Properties of metals
• Non-metals
→ Physical properties of non-metals
→ Chemical Properties of metals
• Difference between metals and non-metals
• Reaction with Acids
• Reaction with Bases
This document contains answers to questions about solutions, mixtures, and related concepts. It defines a solution as a homogeneous mixture that exists as a single phase, while a mixture can exist in multiple phases. Alloys are considered solutions because they are homogeneous mixtures like brass. The Dead Sea is rich in salts that prevent any life from existing due to high salinity. Percentage calculations do not require the chemical formula of the solute, while molarity calculations do to determine molar mass and moles of solute. Solubility increases with temperature for salts like KNO3 and NaNO3 that dissolve endothermically.
1. Filtering would be used to separate sand and water.
2. Fractional distillation separates alcohol and water based on their different boiling temperatures.
3. Coffee powder is made by filtering coffee beans boiled in water to remove solids, then evaporating the remaining liquid.
This document provides information about the structure of the atom. It discusses the three main subatomic particles - electrons, protons, and neutrons. It describes the discoveries of these particles by scientists like Thomson, Goldstein, and Chadwick. The document then explains four major atomic models - Thomson's model, Rutherford's model, Bohr's model, and the distribution of electrons in shells. It also discusses concepts like atomic number, mass number, isotopes, isobars, and valency.
This document outlines key concepts about acids, bases, and salts. It defines acids as substances that produce hydrogen ions in water. There are strong acids that fully ionize and weak acids that partially ionize. Bases are oxides or hydroxides of metals. Alkalis are soluble bases that produce hydroxide ions in water. Acids and bases react to form salts and water in a neutralization reaction. The pH scale measures acidity and alkalinity. Indicators change color with pH. There are four types of oxides. Salts contain cations from bases and anions from acids. Common salts have various industrial and domestic uses.
The document defines acids as substances that dissociate in water to produce hydrogen ions, and describes some of their key properties, such as sour taste and turning litmus red. It also discusses important acids like hydrochloric acid and sulfuric acid, and their common uses. Similarly, bases are defined as substances that dissociate to produce hydroxide ions in water. Important bases and their uses are also outlined, along with definitions and examples of salts.
The document discusses metals and non-metals. It describes the physical and chemical properties of metals and non-metals. Metals are lustrous, malleable, ductile and are good conductors of heat and electricity, while non-metals have opposite properties. It also discusses how metals and non-metals react with oxygen, water, acids and how displacement reactions can be used to determine reactivity order. Metals are extracted from ores through processes like enrichment, extraction using chemical/electrochemical methods depending on their reactivity.
This document discusses the properties and states of matter. It defines matter as anything that takes up space and has mass. Physical properties are characteristics that can be observed or measured without changing the substance, such as mass, volume, density, and state of matter (solid, liquid, gas). A mixture is a combination of two or more substances that keep their own properties, while a solution is a type of mixture where particles are evenly mixed but not easy to separate. The state that matter exists in depends on temperature and pressure - it can change states between solid, liquid and gas through physical processes like melting, freezing, boiling, evaporation and condensation that involve adding or removing heat.
Chapter 3.metals and non metals priya jhaPriya Jha
An element is the simplest form of matter that cannot be split into simpler substances or built from simpler substances by any ordinary chemical or physical method. There are 118 elements known to us, out of which 92 are naturally occurring, while the rest have been prepared artificially. Elements are further classified into metals, non-metals, and metalloids based on their properties, which are correlated with their placement in the periodic table.Metals
With the exception of hydrogen, all elements that form positive ions by losing electrons during chemical reactions are called metals. Thus metals are electropositive elements with relatively low ionization energies. They are characterized by bright luster, hardness, ability to resonate sound and are excellent conductors of heat and electricity. Metals are solids under normal conditions except for Mercury.Nonmetals
Elements that tend to gain electrons to form anions during chemical reactions are called non-metals. These are electronegative elements with high ionization energies. They are non-lustrous, brittle and poor conductors of heat and electricity (except graphite). Non-metals can be gases, liquids or solids.Metalloids
Metalloids have properties intermediate between the metals and nonmetals. Metalloids are useful in the semiconductor industry. Metalloids are all solid at room temperature. They can form alloys with other metals. Some metalloids, such as silicon and germanium, can act as electrical conductors under the right conditions, thus they are called semiconductors. Silicon for example appears lustrous, but is not malleable nor ductile (it is brittle - a characteristic of some nonmetals). It is a much poorer conductor of heat and electricity than the metals. The physical properties of metalloids tend to be metallic, but their chemical properties tend to be non-metallic. The oxidation number of an element in this group can range from +5 to -2, depending on the group in which it is located.
Ncert class 10 - science - chapter 3 - metals and non-metalsEswariKumaravel
The document discusses the properties of metals and non-metals. It describes how metals are lustrous, malleable, ductile, and good conductors of heat and electricity, while non-metals lack these properties. Experiments are presented to demonstrate that metals are lustrous, hard except for a few, malleable by hammering into thin sheets, and ductile by pulling into wires. Other experiments show that metals conduct heat by melting wax and conduct electricity by lighting a bulb. The document contrasts how metals and non-metals react with oxygen, water, acids, and how metals react in salt solutions in displacement reactions.
The document provides information about various chemistry concepts related to air and water:
- It describes chemical tests to identify water and the purification of water supplies through filtration and chlorination.
- The composition of clean air is described as 78% nitrogen, 21% oxygen and small quantities of other gases. Common air pollutants like carbon monoxide and their sources are stated.
- Fractional distillation is outlined as the process used to separate oxygen and nitrogen from liquid air based on their different boiling points.
- Rusting is described as a reaction between iron, air and water that can be prevented by methods like painting and galvanizing to exclude oxygen.
The document discusses acids and bases, including their properties, examples of common acids and bases, and how strong vs. weak acids and bases are classified. Acids are sour, turn litmus red, and contain hydrogen ions. Bases are slippery, turn litmus blue, and contain hydroxide ions. Strong acids and bases have more hydrogen or hydroxide ions respectively and can be caustic.
This document discusses different types of matter and mixtures. It defines pure substances as being made of a single type of matter, either an element or compound. Mixtures contain two or more substances mixed together physically. Pure substances are classified as elements, which cannot be broken down further, or compounds, which contain two or more elements chemically bonded. Mixtures include homogeneous mixtures, where the composition is uniform, and heterogeneous mixtures where it is not. The properties and examples of each type of pure substance and mixture are described.
This document provides an overview of chemical reactions and equations. It discusses chemical changes and how they can be represented by balanced chemical equations. The main types of chemical reactions covered are combination reactions, decomposition reactions, displacement reactions, and oxidation-reduction reactions. Examples of each type of reaction are given. The document also explains how to balance chemical equations by ensuring equal numbers of each type of atom on both sides of the reaction equation.
This document provides an overview of metals and non-metals. It discusses their physical and chemical properties, including how metals react with oxygen, water, acids, and other substances. Metals are solid, malleable, ductile, and good conductors of heat and electricity. They form basic oxides and react vigorously with acids. Non-metals do not have these properties and are usually gases or solids. The document also covers extraction methods for metals and corrosion prevention.
This document discusses types of chemical reactions, including:
1) Combination reactions where two or more reactants combine to form products, such as magnesium combining with oxygen to form magnesium oxide.
2) Displacement reactions which can be metal-metal, where a more reactive metal displaces a less reactive one, or metal-nonmetal where a metal displaces a nonmetal.
3) The document provides examples of combination and displacement reactions and classifies common types of chemical reactions like decomposition, double displacement, and oxidation-reduction reactions.
This document discusses the classification and properties of pure substances and mixtures. It defines pure substances as elements or compounds that consist of a single type of matter, while mixtures contain two or more pure substances mixed together. Mixtures are classified as either homogeneous, containing substances mixed uniformly, or heterogeneous, containing visible particles that can be separated. The document also discusses various techniques for separating components of mixtures like evaporation, centrifugation, distillation and crystallization.
Chemical reactions and equations class 10 CBSEritik
This document discusses chemical reactions and equations. It defines a chemical reaction as a process where reactants are converted into products, which may occur under the influence of a catalyst. It describes how to write chemical equations and balance them by ensuring equal numbers of each type of atom on both sides of the reaction. It also defines and provides examples of different types of chemical reactions: combination, decomposition, displacement, double displacement, and redox reactions. Corrosion and rancidity are discussed as examples of oxidation reactions.
This document discusses various techniques for purifying substances, including filtration, crystallization, distillation, and chromatography. It provides examples of how each technique works and the types of mixtures it can be used to separate. Key points include:
- Filtration separates insoluble solids from liquids by passing the mixture through a filter paper.
- Crystallization forms pure crystals of a soluble solid by slowly evaporating the solvent from a saturated solution.
- Distillation boils a liquid mixture and condenses the vapor to separate components with different boiling points.
- Chromatography separates mixtures by exploiting differences in how substances partition between a stationary and mobile phase.
hello friends this is dattatreya and team.so we all did research on the 2nd chapter of chemistry that is "is matter around us pure so hope you like it and please download it....
Topics Included
• Introduction
• Metals
→ Physical properties of metals
→ Chemical Properties of metals
• Non-metals
→ Physical properties of non-metals
→ Chemical Properties of metals
• Difference between metals and non-metals
• Reaction with Acids
• Reaction with Bases
This document contains answers to questions about solutions, mixtures, and related concepts. It defines a solution as a homogeneous mixture that exists as a single phase, while a mixture can exist in multiple phases. Alloys are considered solutions because they are homogeneous mixtures like brass. The Dead Sea is rich in salts that prevent any life from existing due to high salinity. Percentage calculations do not require the chemical formula of the solute, while molarity calculations do to determine molar mass and moles of solute. Solubility increases with temperature for salts like KNO3 and NaNO3 that dissolve endothermically.
1. Filtering would be used to separate sand and water.
2. Fractional distillation separates alcohol and water based on their different boiling temperatures.
3. Coffee powder is made by filtering coffee beans boiled in water to remove solids, then evaporating the remaining liquid.
1. Filtering would be used to separate sand and water.
2. Fractional distillation separates alcohol and water based on their different boiling points.
3. Coffee powder is made by filtering coffee beans boiled in water to remove solids, then evaporating the liquid to dry the powder.
The document contains multiple choice questions about different science topics including:
- Calculating percentages of solutions
- Factors that affect solubility
- Identifying substances and mixtures
- Recognizing properties of common elements from the periodic table
- Distinguishing between metals and nonmetals
- Differentiating organ systems, organs, tissues, and cells
This document for Class 9 (CBSE), Chapter 2 - Is Matter Around Us Pure, includes MCQs, Match the following, True or False, Fill in the blanks and Very-Short-Answer Questions. Hope you like it.
The lab experiment involved purifying benzoic acid through recrystallization and then using calorimetry to determine its enthalpy of solution. In the first part, 50mg of benzoic acid was dissolved in hot water and filtered. Impurities were removed through boiling and activated charcoal. The solution was cooled and crystals were formed, separated from water using ethanol, and dried. In the second part, the enthalpy of solution was determined using a calorimeter by dissolving the purified benzoic acid crystals in water and measuring the temperature change.
This document discusses different types of mixtures and separation techniques. It begins by defining a pure substance as a single substance that exists as crystals, while mixtures are impure substances made of two or more substances mixed together. It then discusses homogeneous mixtures like solutions and heterogeneous mixtures like suspensions and colloids. The document goes on to describe various separation techniques including filtration, evaporation, crystallization, distillation, chromatography and provides examples of how each technique can be used to separate different mixtures.
The document discusses various topics related to mixtures and separations:
- It identifies different types of solutions, suspensions, and colloids.
- It investigates how structure and temperature affect solubility of solids in water.
- It distinguishes among solutions, suspensions, and colloids and identifies suitable separation techniques based on differences in component properties of mixtures.
- It describes the extraction of sucrose from sugar cane.
This document discusses mixtures and separations. It begins by defining pure substances and mixtures. It then describes different types of mixtures, including homogeneous mixtures (solutions) and heterogeneous mixtures (suspensions and colloids). Various separation techniques are identified for different types of mixtures, such as filtration, evaporation, crystallization, distillation, and chromatography. Examples are provided to illustrate solubility, separation methods, and chromatography.
This document appears to be a science exam from Immanuel School of Davao for their third periodical examination in Science 4. It contains 40 multiple choice questions testing students on topics like changes in matter, types of energy, physical and chemical changes, mixtures and solutions, atoms and molecules, electricity and circuits, and conservation of energy. The questions are numbered 1 through 40 and are organized into topics that make up 32.5% of the exam on changes in matter, 25% on physical and chemical changes, 5% on pollution, 7.5% on household materials, and 22.5% on energy.
This document discusses the classification and properties of different types of matter. It begins by classifying matter into pure substances and mixtures based on chemical composition. Pure substances are further divided into elements and compounds. Mixtures are classified as homogeneous or heterogeneous based on whether their composition is uniform or not. Various properties of pure substances, mixtures, solutions, colloids and suspensions are described. Common examples are provided. Different techniques for separating components of mixtures like evaporation, centrifugation, filtration etc. are also summarized.
Ch 2 Is Matter Around Us Pure 1.ppt-4-38.pdfssuser329ea9
This document discusses the classification of matter and different types of mixtures. It defines pure substances as those made of a single type of particle, while mixtures contain two or more pure substances. Mixtures are classified as either homogeneous, containing uniformly distributed particles too small to see, or heterogeneous, where particles settle out or can be filtered. Common mixtures discussed include solutions, colloids, and suspensions. Several methods for separating mixtures are also outlined, such as evaporation, centrifugation, chromatography, and distillation.
The document discusses the key differences between elements, compounds, and mixtures. It defines elements as the simplest form of matter that has unique properties, and notes that all substances on the periodic table are elements. Compounds are defined as substances made of two or more elements bonded together that can be broken down through chemical means into simpler substances. Compounds have different properties than their component elements. Mixtures can be either homogeneous, with a uniform composition throughout, or heterogeneous, with a non-uniform composition. The document provides examples of chemical changes and physical changes to further illustrate the differences.
The document discusses various methods of purifying substances, including filtration, crystallization, and evaporation. It provides details on the principles and procedures of these purification techniques. Filtration is used to separate insoluble solids from liquids or solutions. Crystallization produces pure solids from solutions and is used if the solid decomposes upon strong heating. Evaporation removes the solvent from a solution, leaving behind the pure solid, and is used if the solid does not decompose with heat.
The document provides answers to 11 questions about acids, bases and salts. It defines strong and weak acids, and lists differences between acids and bases. It explains that acetic acid is in vinegar, ammonia is basic. Litmus solution comes from lichens and is used as a pH indicator. Distilled water is neutral as shown by litmus. Neutralization reactions form salts and water. Antacids neutralize excess stomach acid; calamine neutralizes ant bites. Factory waste is neutralized before disposal. The last questions discuss indicator color changes with acids and bases.
Classic, mini chemistry experiments- some require materials typically found in a high school chemistry lab, while others are extremely simple. Very straightforward!
This document discusses mixtures and separation techniques. It defines pure substances and mixtures, and describes different types of mixtures like solutions, suspensions, and colloids. Several physical separation methods are described, including filtration, evaporation, crystallization, sublimation, distillation, fractional distillation, use of a separating funnel, and chromatography. These techniques separate mixtures based on differences in properties of the components like solubility, boiling point, and polarity. The document also provides examples to illustrate key concepts and separation processes.
The document is a chemistry textbook section about solutions. It introduces key concepts like mixtures, solutions, solutes and solvents. It describes different techniques for separating mixtures, including filtration, evaporation, distillation and chromatography. It also discusses how solubility is affected by temperature and saturation.
APEX INSTITUTE was conceptualized in May 2008, keeping in view the dreams of young students by the vision & toil of Er. Shahid Iqbal. We had a very humble beginning as an institute for IIT-JEE / Medical, with a vision to provide an ideal launch pad for serious JEE students . We actually started to make a difference in the way students think and approach problems.
Similar to Important questions CLASS 9 IS MATTER AROUND US PURE (20)
Forces cause objects to change their motion. An object at rest will stay at rest and an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force. The greater the mass of the object, the greater the amount of force needed to achieve the same change in motion.
Notes main points FROM THE CHAPTER IS MATTER AREOUND US PUREthesaver
1. Matter can exist as pure substances, mixtures, or compounds. Pure substances are either elements or compounds that have a uniform composition. Mixtures are combinations of substances that retain their individual chemical identities.
2. Mixtures can be either homogeneous, with a uniform composition, or heterogeneous, with a non-uniform composition. Common homogeneous mixtures include solutions and alloys. Common heterogeneous mixtures include mixtures of sand and sugar.
3. There are various techniques that can be used to separate mixtures into their individual components, including filtration, centrifugation, chromatography, distillation, crystallization, and more. The appropriate separation technique depends on the types of substances involved.
Mcq's of class 9 chapter IS MATTER AROUND US PUREthesaver
This document provides 16 multiple choice questions about class 9 science chapter 2 on matter. The questions test understanding of key concepts from the chapter including properties of pure substances, physical and chemical changes, mixtures and compounds. Sample questions ask about defining rusting, identifying homogeneous mixtures, and classifying substances and changes. The document also includes exercises to label elements and compounds, complete a crossword with science terms, and fill in blanks about colloids and separation techniques.
This document contains 33 multiple choice questions about tissues in class 9 science. It tests knowledge about the different types of tissues like epithelial tissue, connective tissue, and muscular tissue. It includes questions about the structure and function of tissues in plants and animals, like which tissue increases the girth of the stem, where adipose tissue is stored in the body, and what type of epithelial cells absorb digested food in the intestine. The document also contains fill-in-the-blank questions to test understanding of tissue terms and concepts.
Important Question with Answer of Tissues class 9thesaver
This document contains 28 extra questions from the chapter Tissues for Class 9 Science students. It includes questions testing knowledge of different plant and animal tissues like xylem, phloem, blood, muscle and epithelial tissues. The questions range from very short to short answer to long answer types. They cover topics like composition of tissues, their structure and functions, and differences between voluntary and involuntary muscles.
The document discusses the four main types of animal tissues: epithelial, connective, muscular, and nervous tissue. Epithelial tissue forms protective and internal layers. Connective tissue develops from mesoderm and binds other tissues. Muscular tissue includes cardiac, smooth, and skeletal muscle and allows movement. Nervous tissue comprises the central and peripheral nervous systems and transmits nerve impulses. Each tissue type has distinct characteristics, components, and functions essential for the structure and operation of the body.
The document discusses plant tissues. There are two main types of plant tissue - meristematic and permanent tissue. Meristematic tissue is dividing tissue found at growth points that allows plants to grow. It includes apical, lateral and intercalary meristem. Permanent tissues are non-dividing and include simple tissues like parenchyma, collenchyma and sclerenchyma, as well as complex tissues like xylem and phloem that transport materials.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
PPT on Direct Seeded Rice presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
(June 12, 2024) Webinar: Development of PET theranostics targeting the molecu...Scintica Instrumentation
Targeting Hsp90 and its pathogen Orthologs with Tethered Inhibitors as a Diagnostic and Therapeutic Strategy for cancer and infectious diseases with Dr. Timothy Haystead.
PPT on Alternate Wetting and Drying presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
Anti-Universe And Emergent Gravity and the Dark UniverseSérgio Sacani
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a0 = cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
Discovery of An Apparent Red, High-Velocity Type Ia Supernova at 𝐳 = 2.9 wi...Sérgio Sacani
We present the JWST discovery of SN 2023adsy, a transient object located in a host galaxy JADES-GS
+
53.13485
−
27.82088
with a host spectroscopic redshift of
2.903
±
0.007
. The transient was identified in deep James Webb Space Telescope (JWST)/NIRCam imaging from the JWST Advanced Deep Extragalactic Survey (JADES) program. Photometric and spectroscopic followup with NIRCam and NIRSpec, respectively, confirm the redshift and yield UV-NIR light-curve, NIR color, and spectroscopic information all consistent with a Type Ia classification. Despite its classification as a likely SN Ia, SN 2023adsy is both fairly red (
�
(
�
−
�
)
∼
0.9
) despite a host galaxy with low-extinction and has a high Ca II velocity (
19
,
000
±
2
,
000
km/s) compared to the general population of SNe Ia. While these characteristics are consistent with some Ca-rich SNe Ia, particularly SN 2016hnk, SN 2023adsy is intrinsically brighter than the low-
�
Ca-rich population. Although such an object is too red for any low-
�
cosmological sample, we apply a fiducial standardization approach to SN 2023adsy and find that the SN 2023adsy luminosity distance measurement is in excellent agreement (
≲
1
�
) with
Λ
CDM. Therefore unlike low-
�
Ca-rich SNe Ia, SN 2023adsy is standardizable and gives no indication that SN Ia standardized luminosities change significantly with redshift. A larger sample of distant SNe Ia is required to determine if SN Ia population characteristics at high-
�
truly diverge from their low-
�
counterparts, and to confirm that standardized luminosities nevertheless remain constant with redshift.
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
JAMES WEBB STUDY THE MASSIVE BLACK HOLE SEEDSSérgio Sacani
The pathway(s) to seeding the massive black holes (MBHs) that exist at the heart of galaxies in the present and distant Universe remains an unsolved problem. Here we categorise, describe and quantitatively discuss the formation pathways of both light and heavy seeds. We emphasise that the most recent computational models suggest that rather than a bimodal-like mass spectrum between light and heavy seeds with light at one end and heavy at the other that instead a continuum exists. Light seeds being more ubiquitous and the heavier seeds becoming less and less abundant due the rarer environmental conditions required for their formation. We therefore examine the different mechanisms that give rise to different seed mass spectrums. We show how and why the mechanisms that produce the heaviest seeds are also among the rarest events in the Universe and are hence extremely unlikely to be the seeds for the vast majority of the MBH population. We quantify, within the limits of the current large uncertainties in the seeding processes, the expected number densities of the seed mass spectrum. We argue that light seeds must be at least 103 to 105 times more numerous than heavy seeds to explain the MBH population as a whole. Based on our current understanding of the seed population this makes heavy seeds (Mseed > 103 M⊙) a significantly more likely pathway given that heavy seeds have an abundance pattern than is close to and likely in excess of 10−4 compared to light seeds. Finally, we examine the current state-of-the-art in numerical calculations and recent observations and plot a path forward for near-future advances in both domains.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Mending Clothing to Support Sustainable Fashion_CIMaR 2024.pdfSelcen Ozturkcan
Ozturkcan, S., Berndt, A., & Angelakis, A. (2024). Mending clothing to support sustainable fashion. Presented at the 31st Annual Conference by the Consortium for International Marketing Research (CIMaR), 10-13 Jun 2024, University of Gävle, Sweden.
CLASS 12th CHEMISTRY SOLID STATE ppt (Animated)eitps1506
Description:
Dive into the fascinating realm of solid-state physics with our meticulously crafted online PowerPoint presentation. This immersive educational resource offers a comprehensive exploration of the fundamental concepts, theories, and applications within the realm of solid-state physics.
From crystalline structures to semiconductor devices, this presentation delves into the intricate principles governing the behavior of solids, providing clear explanations and illustrative examples to enhance understanding. Whether you're a student delving into the subject for the first time or a seasoned researcher seeking to deepen your knowledge, our presentation offers valuable insights and in-depth analyses to cater to various levels of expertise.
Key topics covered include:
Crystal Structures: Unravel the mysteries of crystalline arrangements and their significance in determining material properties.
Band Theory: Explore the electronic band structure of solids and understand how it influences their conductive properties.
Semiconductor Physics: Delve into the behavior of semiconductors, including doping, carrier transport, and device applications.
Magnetic Properties: Investigate the magnetic behavior of solids, including ferromagnetism, antiferromagnetism, and ferrimagnetism.
Optical Properties: Examine the interaction of light with solids, including absorption, reflection, and transmission phenomena.
With visually engaging slides, informative content, and interactive elements, our online PowerPoint presentation serves as a valuable resource for students, educators, and enthusiasts alike, facilitating a deeper understanding of the captivating world of solid-state physics. Explore the intricacies of solid-state materials and unlock the secrets behind their remarkable properties with our comprehensive presentation.
Important questions CLASS 9 IS MATTER AROUND US PURE
1. IMPORTANT QUESTIONS
IS MATTER AROUND US PURE
1. Try segregating the things around you as pure substances or mixtures.
Ans. You can do it by yourself like try mixing chalk powder and water then separate
them.
2. Classify each of the following as a homogeneous or heterogeneous mixture.
soda water, wood, air, soil, vinegar, filtered tea.
Ans.
3. How would you confirm that a colourless liquid given to you is pure water?
Ans. If we allow the given liquid to evaporate by heating it as in a clean china dish
so:
any residue remaining in the china dish will indicate that water is not
pure but contains impurities.
no residue in china dish will indicate that water is pure.
4. Which of the following materials fall in the category of a “pure substance”?
(a)Ice
(b)Milk
(c)Iron
(d)Hydrochloricacid
(e)Calciumoxide
(f)Mercury
(g)Brick
2. (h)Wood
(i) Air.
Ans. Pure substances are: ice, iron, hydrochloric acid, calcium oxide, mercury.
5. Identify the solutions among the following mixtures.
(a) Soil
(b) Sea water
(c) Air
(d) Coal
(e) Soda water.
Ans. Sea water, air and soda water are solutions.
6. Which of the following will show “Tyndall effect”?
(a) Salt solution
(b)Milk
(c) Copper sulphate solution
(d) Starch solution.
Ans. Milk and starch solution have larger particles since they are not true solutions
so they will show tyndall effect.
7. Classify the following into elements, compounds and mixtures.
(a) Sodium
(b) Soil
(c) Sugar solution
(d) Silver
(e) Calcium carbonate
3. (f) Tin
(g) Silicon
(h) Coal
(i) Air
(j) Soap
(k) Methane
(l) Carbon dioxide
(m) Blood
Ans.
8. Which of the following are chemical changes?
(a) Growth of a plant
(b) Rusting of iron
(c) Mixing of iron filings and sand
(d) Cooking of food
(e) Digestion of food
(f) Freezing of water
(g) Burning of a candle.
Ans. Rusting of iron, cooking of food, digestion of food, burning of a candle are
chemical changes.
4. 9.Which of the following solution scatter light?
(a) colloidal solution
(b) suspension
(c) both
(d) none
Ans. (c) both
10. Which of the following methods would you use to separate cream from
milk?
(a) fractional distillation
(b) distillation
(c) centrifugation
(d) filtration
Ans. (c) centrifugation
11.Cooking of food and digestion of food:
(a) are both physical processes
(b) are both chemical processes
(c) cooking is physical whereas digestion is chemical
(d) cooking is chemical whereas digestion physical
Ans. (b) are both chemical processes
12. Mercury and Bromine are both
(a) liquid at room temperature
5. (b) solid at room temperature
(c) gases at room temperature
(d) both (a) and (b)
Ans. (a) liquid at room temperature
13. Blood and sea water are:
(a) both mixtures
(b) both are compound
(c) blood is a mixture whereas sea water is a compound
(d) blood is a compound and sea water is a mixture
Ans. (a) both mixtures
14. Sol and Gel are examples of examples of
(a) Solid-solid colloids
(b) Sol is a solid-liquid colloid and Gel is liquid solid colloid
(c) Sol is a solid-solid colloid and Gel is a solid-liquid colloid
(d) Sol is a liquid-solid colloid and Gel is a solid-liquid colloid
Ans. (b) Sol is a solid-liquid colloid and Gel is liquid solid colloid
15. In a water-sugar solution:
(1) water is solute and sugar is solvent
(2) water is solvent and sugar is solute
(3) water is solute and water is also solute
(4) none of these
Ans. (b) Sol is a solid-liquid colloid and Gel is liquid solid colloid
6. 16. Boron and carbon:
(a) are metalloids
(b) boron is metalloid and carbon is non-metal
(c) boron is metallic and carbon is a metal
(d) boron is non-metal and carbon is a metalloid
Ans. (a) are metalloids
2 Marks Questions
1. What is meant by a substance?
Ans. Substance can be defined as that kind of matter where constituent particles
cannot be separated from each other by any physical process since they are all similar
in chemical properties.
2. How will you separate a mixture containing kerosene and petrol (difference
in their boiling points is more than ), which are miscible with each other?
Ans. We can separate a mixture containing kerosene and petrol by distillation
technique since difference in their boiling points is more than . So through
distillation we can get them separated.
3. Name the technique to separate
(i)butterfrom curd,
(ii) salt from sea-water,
(iii) camphor from salt.
Ans. (i) centrifugation method.
(ii) evaporation method.
(iii) sublimation method.
7. 4. What type of mixtures are separated by the technique of crystallisation?
Ans. From impure samples of solids, pure solid crystals can be obtained by the
method of crystallization for eg to obtain pure sugar from impure sample of the same.
5. What is a mixture? What are its various types?
Ans. A mixture is constituted by more than one substance (element/or compound)
mixed in any proportion. They are of two types:
(a) Homogenous mixture
(b) Heterogeneous mixture
6. Define solute, solvent and solution?
Ans. Solute: - It is the component of the solution which is added to the solvent.
Solvent: - It is the component of the solution to which the solute is added or it
dissolves the solute.
Solution: - It is constituted by solute and solvent.
For e.g. solution of NaCl- has NaCl as solute and water as solvent.
7. What is a solution? What are the properties of solution?
Ans. A solution is a homogenous mixture of two or more substance. The various
properties of solution are: -
(a) It is a homogenous mixture.
(b) The particles of a solution are smaller than 1nm and hence cannot be seen by
naked eyes.
(c) It does not scatter the beam of light passing through it.
(d) The component of solution cannot be separated from each other by the process
of filtration.
8. Differentiate between elements and compounds.
8. Ans.
9. What is tyndall effect? Which kinds of solution show it?
Ans. The scattering of a beam of light by particles of solution when light is passed
through it is called tyndall effect. Those solutions where size of the particle is very
small for e.g. colloidal solution shows tyndall effect.
10. Differentiate between homogeneous and heterogeneous mixture?
Ans.
11. What is centrifugation? Where it is used?
Ans. Centrifugation is a technique used for separation of constituents of mixture and
is based upon the principle that denser particles stay at bottom and lighter particles
stays at the top when spun rapidly. It is used separate cream from milk.
12. What is a suspension? What are the properties of suspension?
Ans. A suspension is a heterogeneous mixture in which the solute particles do not
dissolve but remains suspended throughout the bulk of the medium.
9. Properties of suspension:
(a) The particles can be seen by naked eyes.
(b) They scatter a beam of light passing through it.
(c) The particles settle down when left undisturbed.
3 Marks Questions
1. List the points of differences between homogeneous and heterogeneous
mixtures.
Ans.
2. Differentiate between homo generous and heterogeneous mixtures with
examples.
Ans.
3. How are sol, solution and suspension different from each other?
10. Ans.
4. To make a saturated solution,36 g of sodium chloride is dissolved in 100 g of
water at293 K. Find its concentration at this temperature.
Ans. Mass of sodium chloride (solute) = 36 g
Mass of water (solvent) = 100 g
Mass of solution = 36 + 100 = 136 g
Therefore, concentration percentage = mass of solute/mass of solution
=
= 26.47 %
5.Classify the following as chemical or physical changes:
• cutting of trees,
• melting of butter in a pan,
• rusting of almirah,
• boiling of water to form steam,
• passing of electric current, through water and the water breaking down into
hydrogen and oxygen gases,
• dissolving common salt in water,
• making a fruit salad with raw fruits, and
• burning of paper and wood.
Ans. cutting of trees = chemical change
11. melting of butter in a pan = physical change
rusting of almirah = chemical change
boiling of water to form steam = physical change
passing of electric current, through water and the water breaking down into hydrogen
and oxygen gases = chemical change
dissolving common salt in water = physical change
making a fruit salad with raw fruits = physical change
burning of paper and wood = chemical change
6. Which separation techniques will you apply for the separation of the
following?
(a) Sodium chloride from its solution in water.
(b) Ammonium chloride from a mixture containing sodium chloride and
ammonium chloride.
(c) Small pieces of metal in the engine oil of a car.
(d) Different pigments from an extract of flower petals.
(e) Butter from curd.
(f) Oil from water.
(g) Tea leaves from tea.
(h) Iron pins from sand.
(i) Wheat grains from husk.
(j) Fine mud particles suspended in water.
Ans. (a) Evaporation method
(b) Sublimation method
(c) by heating and then after filtration
(d) by Chromatography
(e) by method of centrifugation
(f) by using separating funnel
(g) by filtration method using strainer
(h) with the help of a magnet
12. (i) by winnowing
(j) by centrifugation
7. Write the steps you would use for making tea. Use the words solution, solvent,
solute, dissolve, soluble, insoluble, filtrate and residue.
Ans. Take more amount of solvent (water) in a pan and after heating it add little
amount of solute (sugar) to the solvent. Solute will dissolve completely in the solvent
forming true solution, then add tea leaves that are insoluble along with another
soluble liquid milk. After boiling allow filtration with a sieve so the filtrate you
obtain is tea while the residue has tea leaves that are thrown away.
8. Pragya tested the solubility of three different substances at different
temperatures and collected the data as given below(results are given in the
following table, as grams of substance dissolved in 100 grams of water to form
a saturated solution).
(a) What mass of potassium nitrate would be needed to produce a saturated
solution of potassium nitrate in50 grams of water at 313 K?
(b) Pragya makes a saturated solution of potassium chloride in water at 353 K
and leaves the solution to cool at room temperature. What would she observe
as the solution cools? Explain.
(c) Find the solubility of each salt at 293 K. Which salt has the highest solubility
at this temperature?
(d) What is the effect of change of temperature on the solubility of a salt?
Ans. (a) At 313 K temperature the amount of potassium nitrate required was 62g in
100ml of water so in 50g water we will need to dissolve
potassium nitrate.
13. (b) At 373K saturated solution preparation needs 54g potassium nitrate and at room
temperature (293 K) saturation solution formation occurs with 35g potassium nitrate
hence = 54 – 35 = 19g potassium nitrate will precipitate out as undissolved salt.
(c) Solubilities are (in 100 mg of water) 32,36,35,37 respectively for the mentioned
salts and the highest solubility is of ammonium chloride at this temperature.
(d) Solubility of salts is directly proportional to the temperature i.e. if temperature
increases then solubility will increase and if the temperature decreases solubility will
also decrease.
9. Explain the following giving examples.
(a) saturated solution
(b) pure substance
(c) colloid
(d) suspension
Ans. (a) saturated solution: It is a solution in which no more solute particles can be
dissolved at a particular temperature.
(b) pure substance: Such substance that has a uniform composition i.e. has particles
with identical properties is called pure substance eg sugar, salt, water, nitrogen etc.
(c) colloid: It is a kind of heterogeneous mixture/solution in which particle size is
between 1nm and 1000nm. Colloids have dispersion medium and dispersed phase.eg
smoke, milk, shaving cream, jelly, cheese etc.
(d) suspension: It is a kind of heterogeneous mixture in which insoluble solid
particles remain suspended in the medium and dispersion particles are visible to the
unaided eyes.eg muddy river water, chalk powder in water, dust storm, sand in water
etc.
10. Write a method to separate different gases from air.
Ans. Air is a homogeneous mixture of various gases.
It can be separated from its various components by fractional distillation.
(a) First compress and cool the air by increasing the pressure and decreasing the
temperature.
14. (b) We obtain the liquid air; now allow the liquid air to warm up slowly in fractional
distillation column.
(c) The various gases separate from each other according to their boiling points at
various heights of the fractionally column.
11. What is a colloid? What are its various properties?
Ans. Colloids are the heterogeneous mixture of substances in which the particle size
is too small and cannot be seen by naked eyes.
(1) It is a heterogeneous mixture, but appears homogenous.
(2) The size of particles is too small to be individually seen by naked eyes.
(3) They scatter beam of light passing through it and makes its path visible.
(4) The particles of colloid do not settle down when left undisturbed.
12. A solution contains 60g of NaCl in 400g of water. Calculate the
concentration in term of mass by mass percentage of the solution.
Ans. Mass of solute (NaCl) = 60g
Mass of solvent (water) = 400g
Mass of solution = Mass of solute + Mass of solvent
= 60 + 400 = 460g
Mass percentage of solution =
= = = 13.4%
13. Differentiate between metals and non metal based upon the various
properties that they show.
15. Ans.
14. Differentiate between mixtures and compound by giving appropriate
examples?
Ans.
15. Write a method to separate a mixture of salt and ammonium chloride?
Ans. A mixture of salt and ammonium chloride can be separated by the process of
sublimation. Since ammonium chloride changes directly from solid into gaseous
state on heating and salt does not so this principle is used to the mixture of two.
(1) The mixture of NH4Cl (ammonium chloride) and salt is taken in a china dish
inside an inverted funnel.
(2) The mixture is heated and because NH4Cl sublimates thus changes into vapours
directly.
(3) Salt which is non-sublimable substance settles into the inverted funnel.
16. Separation of NH4Cl salt by sublimation
16. What is crystallization? Where is it used? Why is this better than simple
evaporation technique?
Ans. Crystallization is a process that separates a pure solid in the form of crystals
from its solution. It is used to purify solids. For e.g. salt from sea water is purified
using crystallization. It is a better technique than simple evaporation because:
(a) Some solid may decompose or get charred on heating to dryness during
evaporation.
(b) On evaporation, some of the impurities still remain dissolved in the solution.
17. What is chromatography? What are its various applications and underline
the basic principle involved?
Ans. Chromatography is a technique used for separation of those components whose
solubility in the same solvent is different.
Its various applications are:
(a) It is used to separate different colours in dye.
(b) It is used to separate pigments from natural colours.
(c) It is used to separate drugs from blood.
The basic principle in chromatography is the different solutes have different
solubility in the same solvent. For e.g. if we take a spot of ink on a paper and dip it
in water than that coloured component which is more soluble in water rises faster
and the other which is less soluble remains at the bottom and hence the two
component can be separated.
17. 18. A solution of acid is labeled is 95%. What is the mass of this that must
be diluted with water to get 5L of solution containing 10 g of per litre?
Ans. 1L of the diluted solution must contain 10 g of .
Therefore, 5L of the diluted solution must contain 50 g of .
The concentration of the acid in the bottle is 95%.
This means that
95 g of is present in 100 g of the acid solution
50 g of will be present in
52.64 g of the solution
:
Search