The presentation "Laws of chemical combinations" is prepared for grade 9, for educational purpose. the topics include all the four Laws of Chemical Combination.
This document summarizes the five major laws of chemical combination:
1) Law of Conservation of Mass - the total mass is conserved in chemical reactions
2) Law of Definite Proportions - a chemical compound always has the same proportions of elements by mass
3) Law of Multiple Proportions - when two elements react to form multiple compounds, the ratios of one element are whole number multiples
4) Law of Reciprocal Proportions - ratios of elements combining with a third are related to their direct combination
5) Gay-Lussac's Law of Gaseous Volumes - reacting gases combine in simple volume ratios at constant temperature and pressure
The document discusses several important laws and concepts in chemistry:
1) The Law of Constant Composition states that a chemical compound always contains the same elements in the same proportions by mass.
2) The Law of Conservation of Mass says that mass is neither created nor destroyed in chemical reactions.
3) The Law of Multiple Proportions states that when two elements form more than one compound, the ratios of the masses of one element that combine with a fixed mass of the other element are ratios of small whole numbers.
4) Concepts like molar mass, the mole, and stoichiometry provide quantitative relationships between substances in chemical equations and reactions.
The document discusses the law of conservation of mass, which states that matter is neither created nor destroyed in a chemical reaction. It provides an example showing that the total mass of reactants (calcium carbonate at 100g) equals the total mass of products (calcium oxide at 56g and carbon dioxide at 44g). The document also presents a chemistry problem demonstrating that the law is verified when the masses of reactants and products are shown to be equal.
This document classifies and describes various types of hydrocarbons including alkanes, alkenes, alkynes, and benzene. It discusses their structures, methods of preparation from other compounds, and common chemical reactions. Key details provided include the IUPAC nomenclature rules for alkanes and cycloalkanes, reactions of alkenes with halogens, acids, and hydrogen, and benzene reactions such as nitration, sulfonation, halogenation, and Friedel-Crafts additions and acylations.
The document discusses empirical and molecular formulas. An empirical formula shows the simplest whole number ratio of atoms in a compound, while a molecular formula shows the exact number of each atom. To calculate molecular formula from empirical formula: 1) make a table with elements, percentages, atomic masses, moles, and simplest ratios; 2) the empirical formula mass is the sum of the atoms' masses; 3) divide the molar mass by the empirical formula mass to get the common factor for the molecular formula. Two examples are given to calculate empirical and molecular formulas from percentage compositions and molar masses.
This document discusses key concepts in chemical thermodynamics including:
- Thermodynamics deals with different forms of energy and quantitative relationships between them. Chemical thermodynamics focuses on chemical changes.
- Systems, surroundings, boundaries, closed/open/isolated systems, and state functions like internal energy are defined.
- The first law of thermodynamics states that energy is conserved and can be converted between different forms like work and heat but not created or destroyed.
Atoms are the smallest particles that make up all matter. John Dalton's atomic theory states that all matter is made of tiny indivisible particles called atoms. Atoms of different elements have different masses and chemical properties. Two or more atoms can combine to form molecules, which are the smallest units that retain the properties of a substance. Molecules are formed when atoms bond together via chemical bonds and are the smallest particles that can exist independently. Common examples of molecules include water (H2O) and oxygen (O2).
This document summarizes the five major laws of chemical combination:
1) Law of Conservation of Mass - the total mass is conserved in chemical reactions
2) Law of Definite Proportions - a chemical compound always has the same proportions of elements by mass
3) Law of Multiple Proportions - when two elements react to form multiple compounds, the ratios of one element are whole number multiples
4) Law of Reciprocal Proportions - ratios of elements combining with a third are related to their direct combination
5) Gay-Lussac's Law of Gaseous Volumes - reacting gases combine in simple volume ratios at constant temperature and pressure
The document discusses several important laws and concepts in chemistry:
1) The Law of Constant Composition states that a chemical compound always contains the same elements in the same proportions by mass.
2) The Law of Conservation of Mass says that mass is neither created nor destroyed in chemical reactions.
3) The Law of Multiple Proportions states that when two elements form more than one compound, the ratios of the masses of one element that combine with a fixed mass of the other element are ratios of small whole numbers.
4) Concepts like molar mass, the mole, and stoichiometry provide quantitative relationships between substances in chemical equations and reactions.
The document discusses the law of conservation of mass, which states that matter is neither created nor destroyed in a chemical reaction. It provides an example showing that the total mass of reactants (calcium carbonate at 100g) equals the total mass of products (calcium oxide at 56g and carbon dioxide at 44g). The document also presents a chemistry problem demonstrating that the law is verified when the masses of reactants and products are shown to be equal.
This document classifies and describes various types of hydrocarbons including alkanes, alkenes, alkynes, and benzene. It discusses their structures, methods of preparation from other compounds, and common chemical reactions. Key details provided include the IUPAC nomenclature rules for alkanes and cycloalkanes, reactions of alkenes with halogens, acids, and hydrogen, and benzene reactions such as nitration, sulfonation, halogenation, and Friedel-Crafts additions and acylations.
The document discusses empirical and molecular formulas. An empirical formula shows the simplest whole number ratio of atoms in a compound, while a molecular formula shows the exact number of each atom. To calculate molecular formula from empirical formula: 1) make a table with elements, percentages, atomic masses, moles, and simplest ratios; 2) the empirical formula mass is the sum of the atoms' masses; 3) divide the molar mass by the empirical formula mass to get the common factor for the molecular formula. Two examples are given to calculate empirical and molecular formulas from percentage compositions and molar masses.
This document discusses key concepts in chemical thermodynamics including:
- Thermodynamics deals with different forms of energy and quantitative relationships between them. Chemical thermodynamics focuses on chemical changes.
- Systems, surroundings, boundaries, closed/open/isolated systems, and state functions like internal energy are defined.
- The first law of thermodynamics states that energy is conserved and can be converted between different forms like work and heat but not created or destroyed.
Atoms are the smallest particles that make up all matter. John Dalton's atomic theory states that all matter is made of tiny indivisible particles called atoms. Atoms of different elements have different masses and chemical properties. Two or more atoms can combine to form molecules, which are the smallest units that retain the properties of a substance. Molecules are formed when atoms bond together via chemical bonds and are the smallest particles that can exist independently. Common examples of molecules include water (H2O) and oxygen (O2).
Presentation is for the first chapter of class 11th Chemistry CBSE board. Presentation is having detailed description for some of the basic concepts like mole concept, matter in our surrounding etc.
The document discusses chemical reactions and stoichiometry. It defines stoichiometry as using ratios to determine quantities of reactants and products in a chemical reaction. It explains that coefficients in a balanced chemical equation represent molar ratios and can be used to determine moles, mass, and volume of substances in a reaction. It provides examples of solving stoichiometry problems, including determining limiting reactants.
John Dalton proposed the first scientific atomic theory, which stated that each chemical element is composed of atoms of a single, unique type that can combine to form chemical compounds. An atom is the fundamental unit of matter and consists of a nucleus containing protons and neutrons surrounded by electrons. Atoms of the same element contain the same number of protons but can vary in the number of neutrons, resulting in different isotopes of that element. Molecules are the smallest fundamental units of compounds made of two or more atoms bonded together.
This document provides an outline for topics to be discussed in an organic chemistry tutorial, including: introduction to organic chemistry; nomenclature; carbon properties including hybridization and bonds; isomers and stereochemistry; chirality of molecules including conformational and configurational isomers; and relative and absolute configuration. The tutorial will cover key organic chemistry concepts such as naming organic compounds, identifying isomers, hybridization principles, and the 3D arrangement of atoms in chiral molecules.
Here are the steps to solve this practice problem:
A. C2H4 + 3O2 → 2CO2 + 2H2O
B. C2H4 = 28 g/mol, O2 = 32 g/mol, CO2 = 44 g/mol, H2O = 18 g/mol
C. If we want 2.25 mol CO2 and the ratio is 2:1, then we need 2.25 * 2 = 4.5 mol C2H4
4.5 mol C2H4 * 28 g/mol = 126 g of C2H4
D. The ratio of H2O to O2 is 2:3. If we have 12 g
The document provides an introduction to stoichiometry including the four types of stoichiometry problems: (1) given and unknown amounts in moles, (2) given amount in moles and unknown in grams, (3) given amount in grams and unknown in moles, and (4) given and unknown amounts in grams. It then works through example problems of each type, calculating amounts of products or reactants using molar ratios derived from balanced chemical equations.
- The mole concept allows chemists to conveniently keep track of large numbers of particles. A mole is defined as 6.02 x 1023 particles, whether atoms, molecules, ions, etc.
- The formula mass (or molar mass) of a compound is the sum of the atomic masses of each element in its chemical formula. It has units of grams per mole (g/mol).
- Calculations involving moles, mass, particles and formula mass allow conversions between the microscopic and macroscopic scales in chemistry.
The document discusses Hess's law, which states that the heat of reaction is the same whether a chemical process occurs in one or multiple steps. Specifically:
- Hess's law allows adding together multiple chemical equations to determine the enthalpy change of the overall equation.
- Two examples are provided to demonstrate calculating the enthalpy change of an overall reaction by combining individual reaction enthalpies.
- In both examples, the individual reactions are rearranged and combined to produce the overall reaction, and the enthalpy terms are summed to find the enthalpy change of the overall reaction.
This document discusses ionic and metallic bonding. It explains that ions are formed when atoms gain or lose electrons to achieve stable noble gas electron configurations. Metals form cations by losing electrons while nonmetals form anions by gaining electrons. Ionic compounds contain cations and anions in ratios represented by chemical formulas. Metallic bonding occurs via delocalized valence electrons that are shared between metal atoms.
The document outlines 5 main types of chemical reactions: synthesis, decomposition, single replacement, double replacement, and combustion. It provides examples of each type of reaction and describes their key characteristics. Synthesis reactions combine two or more reactants to form one product. Decomposition reactions involve a single reactant breaking down into multiple products. Single replacement reactions involve one element replacing another in a compound. Double replacement reactions involve two compounds swapping parts to form two new compounds. Combustion reactions involve organic compounds burning in oxygen to produce carbon dioxide and water.
In the late 18th century, French chemist Antoine Lavoisier recognized the importance of accurate measurements in chemistry. He extensively studied combustion and discovered it involved reaction with oxygen. He also established the law of conservation of mass, which states that mass is neither created nor destroyed in chemical reactions, though atoms may be rearranged. A chemical equation balances the reactants and products to show equal numbers of each type of atom.
An element is a pure substance that cannot be separated into simpler substances. There are 91 naturally occurring elements on Earth. Elements are not equally abundant, with hydrogen, oxygen, and silicon making up most of the mass of the universe and Earth's crust respectively. Compounds are combinations of elements that have properties different from their constituent elements. Compounds combine elements in definite proportions by mass regardless of amount. The law of multiple proportions states that when different compounds are formed from the same elements, different masses of one element will combine with the same mass of another element in ratios of small whole numbers.
This document discusses relative atomic mass and relative molecular mass. It provides examples to calculate these values.
The key points are:
1. Relative atomic mass (Ar) is the average mass of a single atom of an element compared to 1/12 the mass of one carbon-12 atom.
2. The relative molecular mass (Mr) of a molecule is the sum of the relative atomic masses of all the atoms in the molecule.
3. Examples are provided to calculate relative atomic masses and relative molecular masses using atomic mass values and molecular formulas. Formulas, atomic masses, and molecular masses are compared to calculate unknown values.
This document outlines the 5 main types of chemical reactions:
1) Synthesis reactions involve combining two or more substances to form a single product.
2) Decomposition reactions involve a single reactant breaking down into multiple products.
3) Single replacement reactions involve one element replacing another in a compound.
4) Double replacement reactions involve ion exchange between two compounds in solution.
5) Combustion reactions involve oxidation, producing energy, carbon dioxide, and water when oxygen reacts with a fuel.
This document discusses properties and uses of covalent compounds. It states that covalent compounds generally have lower melting and boiling points than ionic compounds. They are also more flexible, flammable, and less soluble in water than ionic compounds. The document notes that many fuels, medicines, clothes, and foods contain covalent bonds. It provides examples such as fuels powering daily life and clothes made from covalent materials. Covalent compounds share electrons between nonmetal atoms rather than transferring electrons.
I Hope You all like it very much. I wish it is beneficial for all of you and you can get enough knowledge from it. Clear and appropriate objectives, in terms of what the audience ought to feel, think, and do as a result of seeing the presentation. Objectives are realistic – and may be intermediate parts of a wider plan.
Avogadro's law states that equal volumes of gases at the same temperature and pressure contain the same number of molecules. The ideal gas law combines Boyle's, Charles', Gay-Lussac's and Avogadro's gas laws into one equation, PV=nRT, which relates the pressure (P), volume (V), number of moles (n), temperature (T) of an ideal gas. The ideal gas law accurately describes gas behavior at normal room temperature and pressure but real gases deviate from ideal behavior at high pressures due to intermolecular forces or at low temperatures where particle volume is significant.
This document discusses different types of chemical bonds: ionic bonds form when electrons are transferred between atoms, while covalent bonds form when electrons are shared between atoms. Ionic bonds occur between oppositely charged ions and result in crystalline solids with high melting points that conduct electricity when melted. Covalent bonds share electron pairs to achieve stability, and can be nonpolar or polar depending on electron distribution. Compounds formed by covalent bonding exist as gases, liquids or solids with low melting points and poor conductivity. Coordinate covalent bonds involve electron sharing where both electrons come from the same atom. Chemical bonding occurs for atoms to achieve stable electron configurations.
The document discusses several key concepts in chemistry including Dalton's atomic theory, how compounds are formed, and laws of chemical combination. It specifically examines the law of conservation of matter proposed by Antoine Lavoisier, which states that the total mass of the reactants equals the total mass of the products in a chemical reaction. The document also explores Joseph Louis Proust's law of definite proportions, which specifies that the elements in a compound always combine in the same proportions by mass. An experiment is described demonstrating that the proportions of copper and oxygen in copper oxide samples were always in a 4:1 ratio, verifying the law.
Presentation is for the first chapter of class 11th Chemistry CBSE board. Presentation is having detailed description for some of the basic concepts like mole concept, matter in our surrounding etc.
The document discusses chemical reactions and stoichiometry. It defines stoichiometry as using ratios to determine quantities of reactants and products in a chemical reaction. It explains that coefficients in a balanced chemical equation represent molar ratios and can be used to determine moles, mass, and volume of substances in a reaction. It provides examples of solving stoichiometry problems, including determining limiting reactants.
John Dalton proposed the first scientific atomic theory, which stated that each chemical element is composed of atoms of a single, unique type that can combine to form chemical compounds. An atom is the fundamental unit of matter and consists of a nucleus containing protons and neutrons surrounded by electrons. Atoms of the same element contain the same number of protons but can vary in the number of neutrons, resulting in different isotopes of that element. Molecules are the smallest fundamental units of compounds made of two or more atoms bonded together.
This document provides an outline for topics to be discussed in an organic chemistry tutorial, including: introduction to organic chemistry; nomenclature; carbon properties including hybridization and bonds; isomers and stereochemistry; chirality of molecules including conformational and configurational isomers; and relative and absolute configuration. The tutorial will cover key organic chemistry concepts such as naming organic compounds, identifying isomers, hybridization principles, and the 3D arrangement of atoms in chiral molecules.
Here are the steps to solve this practice problem:
A. C2H4 + 3O2 → 2CO2 + 2H2O
B. C2H4 = 28 g/mol, O2 = 32 g/mol, CO2 = 44 g/mol, H2O = 18 g/mol
C. If we want 2.25 mol CO2 and the ratio is 2:1, then we need 2.25 * 2 = 4.5 mol C2H4
4.5 mol C2H4 * 28 g/mol = 126 g of C2H4
D. The ratio of H2O to O2 is 2:3. If we have 12 g
The document provides an introduction to stoichiometry including the four types of stoichiometry problems: (1) given and unknown amounts in moles, (2) given amount in moles and unknown in grams, (3) given amount in grams and unknown in moles, and (4) given and unknown amounts in grams. It then works through example problems of each type, calculating amounts of products or reactants using molar ratios derived from balanced chemical equations.
- The mole concept allows chemists to conveniently keep track of large numbers of particles. A mole is defined as 6.02 x 1023 particles, whether atoms, molecules, ions, etc.
- The formula mass (or molar mass) of a compound is the sum of the atomic masses of each element in its chemical formula. It has units of grams per mole (g/mol).
- Calculations involving moles, mass, particles and formula mass allow conversions between the microscopic and macroscopic scales in chemistry.
The document discusses Hess's law, which states that the heat of reaction is the same whether a chemical process occurs in one or multiple steps. Specifically:
- Hess's law allows adding together multiple chemical equations to determine the enthalpy change of the overall equation.
- Two examples are provided to demonstrate calculating the enthalpy change of an overall reaction by combining individual reaction enthalpies.
- In both examples, the individual reactions are rearranged and combined to produce the overall reaction, and the enthalpy terms are summed to find the enthalpy change of the overall reaction.
This document discusses ionic and metallic bonding. It explains that ions are formed when atoms gain or lose electrons to achieve stable noble gas electron configurations. Metals form cations by losing electrons while nonmetals form anions by gaining electrons. Ionic compounds contain cations and anions in ratios represented by chemical formulas. Metallic bonding occurs via delocalized valence electrons that are shared between metal atoms.
The document outlines 5 main types of chemical reactions: synthesis, decomposition, single replacement, double replacement, and combustion. It provides examples of each type of reaction and describes their key characteristics. Synthesis reactions combine two or more reactants to form one product. Decomposition reactions involve a single reactant breaking down into multiple products. Single replacement reactions involve one element replacing another in a compound. Double replacement reactions involve two compounds swapping parts to form two new compounds. Combustion reactions involve organic compounds burning in oxygen to produce carbon dioxide and water.
In the late 18th century, French chemist Antoine Lavoisier recognized the importance of accurate measurements in chemistry. He extensively studied combustion and discovered it involved reaction with oxygen. He also established the law of conservation of mass, which states that mass is neither created nor destroyed in chemical reactions, though atoms may be rearranged. A chemical equation balances the reactants and products to show equal numbers of each type of atom.
An element is a pure substance that cannot be separated into simpler substances. There are 91 naturally occurring elements on Earth. Elements are not equally abundant, with hydrogen, oxygen, and silicon making up most of the mass of the universe and Earth's crust respectively. Compounds are combinations of elements that have properties different from their constituent elements. Compounds combine elements in definite proportions by mass regardless of amount. The law of multiple proportions states that when different compounds are formed from the same elements, different masses of one element will combine with the same mass of another element in ratios of small whole numbers.
This document discusses relative atomic mass and relative molecular mass. It provides examples to calculate these values.
The key points are:
1. Relative atomic mass (Ar) is the average mass of a single atom of an element compared to 1/12 the mass of one carbon-12 atom.
2. The relative molecular mass (Mr) of a molecule is the sum of the relative atomic masses of all the atoms in the molecule.
3. Examples are provided to calculate relative atomic masses and relative molecular masses using atomic mass values and molecular formulas. Formulas, atomic masses, and molecular masses are compared to calculate unknown values.
This document outlines the 5 main types of chemical reactions:
1) Synthesis reactions involve combining two or more substances to form a single product.
2) Decomposition reactions involve a single reactant breaking down into multiple products.
3) Single replacement reactions involve one element replacing another in a compound.
4) Double replacement reactions involve ion exchange between two compounds in solution.
5) Combustion reactions involve oxidation, producing energy, carbon dioxide, and water when oxygen reacts with a fuel.
This document discusses properties and uses of covalent compounds. It states that covalent compounds generally have lower melting and boiling points than ionic compounds. They are also more flexible, flammable, and less soluble in water than ionic compounds. The document notes that many fuels, medicines, clothes, and foods contain covalent bonds. It provides examples such as fuels powering daily life and clothes made from covalent materials. Covalent compounds share electrons between nonmetal atoms rather than transferring electrons.
I Hope You all like it very much. I wish it is beneficial for all of you and you can get enough knowledge from it. Clear and appropriate objectives, in terms of what the audience ought to feel, think, and do as a result of seeing the presentation. Objectives are realistic – and may be intermediate parts of a wider plan.
Avogadro's law states that equal volumes of gases at the same temperature and pressure contain the same number of molecules. The ideal gas law combines Boyle's, Charles', Gay-Lussac's and Avogadro's gas laws into one equation, PV=nRT, which relates the pressure (P), volume (V), number of moles (n), temperature (T) of an ideal gas. The ideal gas law accurately describes gas behavior at normal room temperature and pressure but real gases deviate from ideal behavior at high pressures due to intermolecular forces or at low temperatures where particle volume is significant.
This document discusses different types of chemical bonds: ionic bonds form when electrons are transferred between atoms, while covalent bonds form when electrons are shared between atoms. Ionic bonds occur between oppositely charged ions and result in crystalline solids with high melting points that conduct electricity when melted. Covalent bonds share electron pairs to achieve stability, and can be nonpolar or polar depending on electron distribution. Compounds formed by covalent bonding exist as gases, liquids or solids with low melting points and poor conductivity. Coordinate covalent bonds involve electron sharing where both electrons come from the same atom. Chemical bonding occurs for atoms to achieve stable electron configurations.
The document discusses several key concepts in chemistry including Dalton's atomic theory, how compounds are formed, and laws of chemical combination. It specifically examines the law of conservation of matter proposed by Antoine Lavoisier, which states that the total mass of the reactants equals the total mass of the products in a chemical reaction. The document also explores Joseph Louis Proust's law of definite proportions, which specifies that the elements in a compound always combine in the same proportions by mass. An experiment is described demonstrating that the proportions of copper and oxygen in copper oxide samples were always in a 4:1 ratio, verifying the law.
This document provides an overview of key concepts in stoichiometry including:
- Dalton's atomic theory and its postulates.
- The laws of stoichiometry such as the law of conservation of mass.
- Avogadro's law and how it relates mass, volume, and number of particles to the mole concept.
- Using the mole concept to perform stoichiometric calculations including limiting reactants.
- Calculating theoretical, experimental, and percent yields of chemical reactions.
- Determining empirical and molecular formulas from percent composition.
This document provides an overview of basic chemistry concepts including:
- Matter can be classified as mixtures or pure substances. Pure substances have a definite composition while mixtures do not.
- Elements are pure substances that cannot be broken down further, and are classified as metals, nonmetals, and metalloids. Compounds are also pure substances but have elements combined in fixed proportions.
- Chemical properties describe reactions that change a substance's composition, while physical properties can be observed without chemical changes.
The document discusses Dalton's atomic theory and concepts related to atoms, molecules, and chemical formulas:
1) Dalton proposed that matter is made of very small indivisible particles called atoms, all atoms of the same element are identical, and atoms cannot be created or destroyed in chemical reactions.
2) The relative atomic mass of an element expresses the mass of one atom of that element relative to 1/12 the mass of one carbon-12 atom. Molecular mass is the sum of the atomic masses of all the atoms in a molecule.
3) A mole is defined as 6.022x10^23 entities (atoms, molecules, etc.) and is used to relate amounts of substances to masses and numbers
This document provides an overview of basic concepts in general chemistry including:
- Atomic and molecular weights and their uses in determining molarity, molality, and equivalency.
- Types of chemical bonds and valency.
- Gas laws including Boyle's, Charles', Dalton's, Henry's and Graham's laws.
- Chemical kinetics and reaction orders including zero-order, first-order and their applications.
Law of multiple proportions and law of definite proportionsNikki Wilkinson
The document discusses several laws related to chemical reactions and composition:
The Law of Definite Proportions states that a chemical compound always has the same proportions by mass of elements. The Law of Multiple Proportions states that when two elements form multiple compounds, the ratios of one element's masses are small whole numbers. The Law of Conservation of Mass states the total mass remains the same in a chemical reaction. Examples and practice problems demonstrate applying these laws.
This document discusses the fundamental laws of chemistry, including:
1. The law of conservation of mass, which states that matter is conserved in chemical reactions.
2. The law of definite proportions and the law of multiple proportions, which describe the fixed ratios in which elements combine.
3. The law of combining volumes and Avogadro's hypothesis, which led to the development of chemical equations representing reactions at the molecular level.
4. The law of conservation of energy, which states that the total energy in a closed system remains constant. Chemical, thermal, and potential energy are discussed in the context of this fundamental law of physics.
1) The document discusses stoichiometry and chemical formulas and equations. It explains that chemical equations represent chemical reactions and must be balanced to conserve atoms.
2) It introduces the mole as a unit that represents 6.02x10^23 particles, allowing for convenient calculation of masses involved in chemical reactions.
3) Formulas and molecular weights are used to determine the percentage composition by mass of elements in compounds. Masses can be converted between moles and numbers of particles using molar mass.
Mole chemistry ppt , ppt for science studentsNishaPandit16
This document provides information about various chemistry concepts including:
- Gay-Lussac's law of combining volumes which states that gases react in simple whole number ratios of their volumes.
- Avogadro's law which established that equal volumes of gases under similar conditions contain the same number of molecules.
- The mole concept which defines one mole as 6.022x10^23 elementary entities like atoms, molecules or ions.
- Empirical and molecular formulas, and how molecular formulas can be determined from empirical formulas and molecular weights.
- Stoichiometry which is based on the law of conservation of mass and allows calculation of amounts of reactants and products from known quantities in a chemical reaction.
Based on the information provided, explain the following observations:
1. When magnesium burns in oxygen, the products are magnesium oxide with a mass ratio of 1 part magnesium to 1 part oxygen.
2. When lead is heated strongly in air, two different oxides are formed - litharge, which is yellow and has a lead-to-oxygen ratio of 1:1, and massicot, which is lighter yellow and has a lead-to-oxygen ratio of 1:2.
3. When hydrogen burns in oxygen, the only product is water with a hydrogen-to-oxygen mass ratio of 1:8.
This document contains notes from a chemistry class. It begins with an introduction and prayer. It then discusses various chemistry topics like balancing chemical equations, types of chemical reactions, limiting and excess reactants, and percent yield. It provides examples and explanations for each topic. Key points covered include the steps to balance equations, the characteristics of different reaction types (synthesis, decomposition, etc.), how to determine the limiting and excess reactants, and how to calculate theoretical and percent yields of a reaction. The document appears to be notes that a teacher provided to students for a general chemistry course.
A molecule is defined as an electrically neutral group of at least two atoms held together by strong chemical bonds. Molecules can be made of a single element or different elements. The modern understanding of molecules evolved from early theories proposed by scientists like Dalton, Avogadro, and Cannizaro in the 19th century. A key concept is that equal volumes of gases contain equal numbers of molecules. Molecules have a definite mass and structure that determines their properties.
This document discusses acid-base reactions and gas-forming reactions. It defines acids and bases according to Arrhenius theory and provides examples of strong and weak acids and bases. Acid-base reactions involve the reaction of hydrogen ions from acids with hydroxide ions from bases to form water. This neutralizes the acid and base. Gas-forming reactions produce a gas, such as reactions of acids with carbonates or metals. These reactions are driven by the formation of products like water, salts, or gases.
This document summarizes acid-base reactions and gas-forming reactions. It defines acids and bases according to Arrhenius theory and provides examples of strong and weak acids and bases. Acid-base reactions involve the reaction of hydrogen ions from acids with hydroxide ions from bases to form water. These reactions are also called neutralization reactions. Gas-forming reactions produce a gas, such as reactions between acids and carbonates or metals. Common gases formed include hydrogen, carbon dioxide, hydrogen sulfide and ammonia.
This document provides an overview of basic chemistry concepts. It defines chemistry as the study of matter and its properties. The main branches of chemistry are described as organic, inorganic, physical, industrial, analytical, biochemistry, and nuclear chemistry. Matter is classified as pure substances or mixtures based on its composition. Elements are the basic units that make up all matter and can exist as atoms or molecules. Chemical properties and reactions are governed by laws such as the law of conservation of mass. The mole concept is introduced as a unit used to quantify the amount of substance.
Here is a one page paper relating chemistry and gases:
Chemistry and gases are intimately related. Many of the most important discoveries and applications in chemistry involve gases. Historically, scientists like Robert Boyle, Jacques Charles, and Joseph Gay-Lussac made seminal discoveries about gas behavior through careful experimentation. Their gas laws laid the foundation for understanding the properties and interactions of gases.
One area where gases play a huge role is in industry and energy. The Haber process converts nitrogen gas and hydrogen gas into ammonia, a key component of fertilizers that have enabled the growth of the global population. Natural gas, composed primarily of methane, heats homes and fuels power plants around the world. Greenhouse gases like carbon dioxide
- Gases exhibit behaviors described by gas laws such as Boyle's law, Charles' law, and Gay-Lussac's law. The ideal gas law combines several gas laws into a single equation relating pressure, volume, temperature, and moles of gas.
- Real gases deviate from ideal gas behavior due to intermolecular forces and molecular size. The van der Waals equation accounts for these factors.
- Kinetic molecular theory explains gas properties in terms of the high-speed motion and infrequent collisions of molecules separated by large distances.
Chapter 3 water and the fitness of the environmentsbarkanic
The document summarizes key concepts about water and its importance for life on Earth. It discusses how the polarity and hydrogen bonding of water molecules leads to emergent properties like cohesion, heat moderation, freezing point, and ability to dissolve solutes. These unique properties, including water's high heat capacity and ability to act as a solvent, contribute significantly to Earth's suitability for life. The document also covers how water dissociates into hydronium and hydroxide ions at different pH levels, affecting organisms.
Similar to Laws of chemical combinations, prepared by Saliha Rais (20)
Chemical bonds are the forces that hold atoms together in molecules and crystals. There are two main types of bonds: ionic and covalent. Ionic bonds involve a complete transfer of electrons between atoms, giving one atom a positive charge and the other a negative charge. Covalent bonds involve sharing of electron pairs between atoms. Covalent bonding can involve single, double or triple bonds with one, two or three shared pairs respectively. Ionic compounds are usually solids with high melting points, while covalent compounds have lower melting points due to weaker intermolecular forces.
Properties of periodic table by Saliha RaisSaliha Rais
The presentation "Properties of Periodic Table" is prepared for grade IX students. The slide show includes a brief description on the properties of elements in the periodic table, that shifts periodically, hence explaining the concept of periodicity. the main topics include Atomic Radii, Ionization energy, Electron affinity and Electronegativity.
Respiratory system with objectives, by Saliha RaisSaliha Rais
The presentation "respiratory system" was prepared for grade VI. this presentation includes short evaluation test in the end, for assessing the learning of students from this. the presentation is according to the syllabus of Usman Public School System, Pakistan.
Cell organelles,prepared by Saliha Rais, for grade 5Saliha Rais
This presentation on Cell organelles cover topics including:
Nucleus, chromosomes, cytoplasm, vacuole, cell membrane, chloroplast, starch grain, cell sap, cell-wall.
At the end of presentation there is a short evaluation test for your self assessment.
I had made this presentation for grade 5.
What is science, prepared by saliha rais, for grade 5.Saliha Rais
The slideshow covers topics including introduction to science and technology, branches of science (biology, chemistry, physics, geology and astronomy), and some famous scientists.
At the end of slideshow, there is a short review test, to evaluate what you have learned from this presentation.
I had made this presentation for grade 5 students.
Its very precise, and beautifully animated.
Soft, hard and heavy water, by Saliha Rais, for grade 9.Saliha Rais
The slide show includes the following topics:
1. hard water
2. soft water
3. causes of hardness of water
4. types of hardness (temporary and permanent)
5. methods to remove temporary hardness (heating and clarks method)
6. methods to remove permanent hardness (with washing soda, caustic soda and zeolite)
7. Heavy water
8. hygroscopic and deliquescent substances
I have made this presentation for grade 9 students.
Simple machines by Saliha Rais, for grade 5.Saliha Rais
The slide show include topics: simple machines, force magnifiers, movement magnifiers, levers and its types. At the end there is a short review/test, so you can assess what you have learned.
I made this for grade 5 students.
Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
The temple and the sanctuary around were dedicated to Asklepios Zmidrenus. This name has been known since 1875 when an inscription dedicated to him was discovered in Rome. The inscription is dated in 227 AD and was left by soldiers originating from the city of Philippopolis (modern Plovdiv).
A Visual Guide to 1 Samuel | A Tale of Two HeartsSteve Thomason
These slides walk through the story of 1 Samuel. Samuel is the last judge of Israel. The people reject God and want a king. Saul is anointed as the first king, but he is not a good king. David, the shepherd boy is anointed and Saul is envious of him. David shows honor while Saul continues to self destruct.
Gender and Mental Health - Counselling and Family Therapy Applications and In...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐍𝐚𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐒𝐜𝐨𝐩𝐞 𝐨𝐟 𝐚𝐧 𝐄𝐧𝐭𝐫𝐞𝐩𝐫𝐞𝐧𝐞𝐮𝐫:
-Define entrepreneurship, distinguishing it from general business activities by emphasizing its focus on innovation, risk-taking, and value creation. Students will describe the characteristics and traits of successful entrepreneurs, including their roles and responsibilities, and discuss the broader economic and social impacts of entrepreneurial activities on both local and global scales.
The chapter Lifelines of National Economy in Class 10 Geography focuses on the various modes of transportation and communication that play a vital role in the economic development of a country. These lifelines are crucial for the movement of goods, services, and people, thereby connecting different regions and promoting economic activities.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
3. LAW OF
CONSERVATION OF
MASS
LAW OF CONSTANT
COMPOSITION/ LAW
OF DEFINITE
PROPORTION
LAW OF MULTIPLE
PROPORTION
LAW OF RECIPROCAL
PROPORTION
LAWS OF CHEMICAL
COMBINATIONS
5. “ In any chemical reaction, the initial
weight of reacting substances is equal
to the final weight of the product.”
6. Lavoisier performed his
experiment in a closed
system. He found that
the total weight of the
system is not changed
in a chemical reaction.
He performed the
decomposition reaction
of the red oxide of
mercury to form
metallic mercury and
oxygen.
7. The mass of the reactants (starting materials)
equals the mass of the products
2Mg (s) + O2 (g) → 2MgO (s)
48.6 g 32.0 g 80.6 g
For example:
8. The law of conservation of mass can be
demonstrated by the union of hydrogen and
oxygen. If the H2O and O2 are weighed before
they unite, it will be found that there
combined weight is equal to the weight of
water formed.
9. The Law of Conservation of Mass is also called
“The Law of Indestructibility of Matter.”
The practical verification of this law was given by
a German Chemist H. Landolt.
Hence the law of conservation of mass can
also be stated as:
“there is no detectable gain or loss of mass in a
chemical reaction.”
12. The law states that:
“ Different samples of the same
compound always contain the same
elements combined together in the
same proportions by mass.
13. OR,
“A chemical compound contains the
same elements in exactly the same
proportions (ratios) by mass
regardless of the size of the sample
or source of the compound.”
14. For example, water
always consists of
oxygen and
hydrogen atoms, and
it is always 89
percent oxygen by
mass and 11 percent
hydrogen by mass.
15. Every sample of
pure water,
though prepared
in the laboratory
or obtained from
rain, river or
water pump,
contains 1 part
hydrogen and 8
parts oxygen by
mass.
16. Berzelius heated 10g lead (Pb) with various
amounts of sulphur (S). But every time he got
exactly 11.56g of Lead sulphide, and the
excess of sulphur was left over.
This shows the significance of law of constant
composition.
18. It states that:
“When two elements combine to form
more than one compound, the masses of
one element which combine with a fixed
mass of the other element are in ratios of
small whole numbers or simple multiple
ratio.”
19. For Example carbon forms 2 stable compounds with
oxygen:
Carbon monoxide (CO): 12 parts by mass of carbon
combines with 16 parts by mass of oxygen.
Carbon dioxide (CO2): 12 parts by mass of carbon
combines with 32 parts by mass of oxygen.
Ratio of the masses of oxygen that combines with a
fixed mass of carbon (12 parts) 16: 32 or 1: 2
21. The excellent example of law of multiple
proportions can be seen when the elements
nitrogen and oxygen combine together to
form a series of compounds.
23. The law states that:
“When two different element separately
combine with the fixed mass of third
element, the proportion in which they
combine with each other shall be either
in the same ratio or some simple
multiple of it.
24. For example, when two
elements C and O combine
separately with H, they form
CH4 (methane) and H2O (water)
respectively.
Now when C and O combine
with each other they form CO2.