Water has unique properties due to its molecular structure and ability to form hydrogen bonds. Water has high surface tension and low vapor pressure due to hydrogen bonding between molecules. The structure of ice is a honeycomb arrangement that makes it less dense than liquid water, allowing ice to float. Aqueous solutions involve water as the solvent and another substance as the solute. Ionic compounds dissolve in water by separating into ions surrounded by water molecules. Solutions can be concentrated or dilute depending on the relative amounts of solute and solvent.
The document discusses electron configuration and the rules for filling electron orbitals in atoms. It explains that electrons exist in energy levels called shells, with each shell able to hold a maximum number of electrons according to the formula 2n2, where n is the shell number. Within shells, electrons occupy specific atomic orbitals that have distinct shapes and are grouped into sublevels. The document outlines Hund's rule and the Aufbau principle for determining the order in which orbitals are filled with electrons. Several examples of deducing full electron configurations for different elements are also provided.
This document discusses models of the atom and electron configuration. It begins by describing historical atomic models including Rutherford's model with a small, dense nucleus and electrons in orbits. Bohr's model improved on this by proposing electrons exist in specific energy levels. The modern quantum mechanical model describes electrons as probability clouds rather than definite orbits. The document then discusses electron configuration notation, including building up configurations using the aufbau principle and exceptions due to Hund's rule and half-filled orbitals. It concludes by introducing atomic spectra and the relationship between light and electron energy levels.
This powerpoint talks about the law Conservation of Mass. You will know who,when and how the discoverer found the Law of Conservation of mass. This is a work that is very good, because it has lots of images, example and you will undestand everything because the vocabulary is simple and anyone can understand it
The document discusses different types of intermolecular forces including London dispersion forces, dipole-dipole forces, dipole-induced dipole forces, ion-dipole interactions, and hydrogen bonding. It provides examples of how these forces influence the properties of substances such as their melting and boiling points. Hydrogen bonding specifically is described as being an important intermolecular force that influences the properties of water, alcohols, and other polar molecules.
Bohr's Theory is based on an early model of atom where electrons travel round the nucleus in a discrete stable numbers of orbit determined by Quantum conditions. This is an extension of Rutherford Model of atom.
Chapter 3.1 : The Atom: The Building Blocks of MatterChris Foltz
John Dalton developed the first atomic theory in 1808 based on experimental evidence from the laws of mass conservation, definite proportions, and multiple proportions. His theory proposed that all matter is composed of extremely small indivisible particles called atoms, atoms of a given element are identical, and atoms of different elements combine in simple whole number ratios to form compounds. Modern atomic theory has since modified Dalton's theory by showing atoms are divisible and some elements exist as different atomic masses.
The document defines key atomic terms like atom, nucleus, protons, neutrons, and electrons. It describes how atoms are made up of a tiny nucleus surrounded by an electron cloud. Atoms of the same element have the same number of protons. The number of neutrons and electrons can vary. The periodic table arranges elements in periods and groups based on their atomic structure and number of valence electrons.
8th Grade Integrated Science Chapter 8 Lesson 1 on Electrons and Energy Levels. This lesson gives a brief introduction of the periodic table, periods, and groups. There is an introduction to metals, nonmetal, and metalloids. This also introduces electrons, energy levels, and the basic idea of bonding.
The document discusses electron configuration and the rules for filling electron orbitals in atoms. It explains that electrons exist in energy levels called shells, with each shell able to hold a maximum number of electrons according to the formula 2n2, where n is the shell number. Within shells, electrons occupy specific atomic orbitals that have distinct shapes and are grouped into sublevels. The document outlines Hund's rule and the Aufbau principle for determining the order in which orbitals are filled with electrons. Several examples of deducing full electron configurations for different elements are also provided.
This document discusses models of the atom and electron configuration. It begins by describing historical atomic models including Rutherford's model with a small, dense nucleus and electrons in orbits. Bohr's model improved on this by proposing electrons exist in specific energy levels. The modern quantum mechanical model describes electrons as probability clouds rather than definite orbits. The document then discusses electron configuration notation, including building up configurations using the aufbau principle and exceptions due to Hund's rule and half-filled orbitals. It concludes by introducing atomic spectra and the relationship between light and electron energy levels.
This powerpoint talks about the law Conservation of Mass. You will know who,when and how the discoverer found the Law of Conservation of mass. This is a work that is very good, because it has lots of images, example and you will undestand everything because the vocabulary is simple and anyone can understand it
The document discusses different types of intermolecular forces including London dispersion forces, dipole-dipole forces, dipole-induced dipole forces, ion-dipole interactions, and hydrogen bonding. It provides examples of how these forces influence the properties of substances such as their melting and boiling points. Hydrogen bonding specifically is described as being an important intermolecular force that influences the properties of water, alcohols, and other polar molecules.
Bohr's Theory is based on an early model of atom where electrons travel round the nucleus in a discrete stable numbers of orbit determined by Quantum conditions. This is an extension of Rutherford Model of atom.
Chapter 3.1 : The Atom: The Building Blocks of MatterChris Foltz
John Dalton developed the first atomic theory in 1808 based on experimental evidence from the laws of mass conservation, definite proportions, and multiple proportions. His theory proposed that all matter is composed of extremely small indivisible particles called atoms, atoms of a given element are identical, and atoms of different elements combine in simple whole number ratios to form compounds. Modern atomic theory has since modified Dalton's theory by showing atoms are divisible and some elements exist as different atomic masses.
The document defines key atomic terms like atom, nucleus, protons, neutrons, and electrons. It describes how atoms are made up of a tiny nucleus surrounded by an electron cloud. Atoms of the same element have the same number of protons. The number of neutrons and electrons can vary. The periodic table arranges elements in periods and groups based on their atomic structure and number of valence electrons.
8th Grade Integrated Science Chapter 8 Lesson 1 on Electrons and Energy Levels. This lesson gives a brief introduction of the periodic table, periods, and groups. There is an introduction to metals, nonmetal, and metalloids. This also introduces electrons, energy levels, and the basic idea of bonding.
- 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.
This document discusses key concepts of evolution including the history of evolutionary theories from creationism to modern ideas like punctuated equilibrium. It covers Darwin and Wallace's model of natural selection and how environmental pressures can lead to speciation. The fundamentals of evolution are explained including variation, inheritance, selection over time. The role of tectonic plate movement in genetic isolation and speciation is described. Various forms of evidence for evolution are listed such as the fossil record, present-day examples, and molecular clocks using mitochondrial DNA.
The document discusses the electronic configuration of atoms, which is the arrangement of electrons in an atom's orbitals. It defines the key terms of energy levels and sublevels, which are the orbitals where electrons are arranged. Examples of electronic configurations are given for several elements, such as iodine and silicon. Rules for determining electronic configuration, such as Aufbau's principle, Pauli's exclusion principle, and Hund's rule are also outlined.
The document discusses chemical formulas and how they are used to express information about the proportions of atoms in compounds. It covers:
- Chemical formulas for covalent molecular compounds, covalent networks, and ionic compounds show the number or ratio of elements present
- Formulas are written using element symbols and subscripts to indicate atom counts
- Valence and Roman numerals are used to indicate an element's bonding tendency which helps write formulas
- Prefixes like mono-, di-, tri- are also used to show atom ratios
- Polyatomic ions, ions formed of multiple elements, are also represented in formulas
- Ionic formulas show the charges of ions present in ionic substances
Molecular compounds are formed when two or more different non-metal atoms combine via covalent bonds, sharing electron pairs. Examples include water, which is made of two hydrogen atoms bonded to one oxygen atom. Molecular compounds have properties like being soft and having low melting points. They are named systematically with the first element, the second as an "-ide", and prefixes to indicate atom amounts, like dinitrogen monoxide for N2O.
Chemical bonds form through different types of attractions between atoms. Ionic bonds form when electrons are transferred from one atom to another, creating oppositely charged ions that are attracted to each other. Covalent bonds form when atoms share electrons equally. Ionic bonds are generally stronger than covalent bonds because more energy is required to overcome the electrostatic forces between ions.
5.4 exothermic and endothermic reactionsMartin Brown
This document discusses exothermic and endothermic reactions. Exothermic reactions release heat, while endothermic reactions absorb heat. Combustion reactions of hydrocarbons like methane and propane are exothermic, producing carbon dioxide, water vapor, and large amounts of heat. The heat of reaction, ΔH, indicates whether a reaction is exothermic (negative ΔH) or endothermic (positive ΔH). Bond energies represent the energy required to break bonds, while heat of combustion measures the heat released from complete combustion. A bomb calorimeter is used to accurately measure heats of combustion by igniting samples in excess oxygen. Hess's law states that the heat change of a reaction depends only on
Cellular respiration involves the breakdown of glucose and other organic molecules to extract energy in the form of ATP. It occurs in three main stages: glycolysis, the Krebs cycle in the mitochondria, and oxidative phosphorylation along the electron transport chain. During aerobic respiration, glucose breakdown yields about 38 ATP molecules total. Without oxygen, anaerobic respiration produces less ATP but allows glycolysis to continue by converting pyruvate into other waste products like lactic acid.
This document discusses photosynthesis in plants. It begins by stating the objectives of understanding the structures, raw materials, and products of photosynthesis. It then describes where photosynthesis takes place inside the chloroplasts in plant leaves. The two stages of photosynthesis are explained as the light-dependent reaction which uses light to produce ATP and NADPH, and the light-independent Calvin cycle which uses those products to fix carbon dioxide into glucose in the chloroplast stroma. Key terms involved in the process are also defined.
Chapter 4.2 : The Quantum Model of the AtomChris Foltz
Louis de Broglie proposed that electrons behave as waves, confined to certain regions around the nucleus at specific energy levels, known as orbitals. The Heisenberg Uncertainty Principle states that it is impossible to know both the position and momentum of an electron simultaneously. Schrodinger's wave equation treats electrons as waves and uses the uncertainty principle to describe the probability of finding electrons in certain orbital regions. Quantum numbers specify the properties of orbitals and electrons, including the principal quantum number for energy level, angular momentum quantum number for orbital shape, and magnetic quantum number for orbital orientation.
This document discusses different types of intermolecular forces: dipole-dipole forces between polar molecules, ion-dipole forces between ions and polar molecules, dispersion forces between all molecules due to induced dipoles, and strong hydrogen bonds between partial charges on hydrogen and electronegative atoms like N, O, F. These intermolecular forces are responsible for determining the properties and phase of substances.
The document discusses Lewis dot structures, which use dots to represent valence electrons around an atomic symbol. It explains that ions have Lewis dot diagrams with fewer (for cations) or more (for anions) dots than the corresponding atom due to gaining or losing electrons. The document provides examples of Lewis dot diagrams for various ions, such as Ca2+ and O2-. It also includes practice problems asking students to draw Lewis dot diagrams for additional ions.
The Kinetic Molecular Theory states that all matter is composed of particles in constant motion. It explains the properties of solids, liquids, and gases by proposing five assumptions: 1) gases consist of tiny particles far apart with mostly empty space, 2) collisions are elastic with no energy loss, 3) particles move rapidly and randomly, 4) there are no attractive or repulsive forces between particles, and 5) average kinetic energy depends on temperature. The theory accounts for gas properties like expansion, fluidity, low density, compressibility, and diffusion/effusion.
Chemistry - Chp 9 - Chemical Names and Formulas - PowerPointMel Anthony Pepito
Here are the formulas or names for the given ionic compounds:
1. Iron (II) Phosphate - Fe3(PO4)2
2. Tin (II) Fluoride - SnF2
3. Potassium Sulfide - K2S
4. Ammonium Chromate - (NH4)2CrO4
5. MgSO4 - Magnesium sulfate
6. FeC - Iron (II) carbide
This document outlines the development of atomic theory from ancient Greek philosophers to modern physics. It describes key contributors such as Democritus, Dalton, Thomson, Rutherford, Bohr, and Schrodinger who proposed models of the atom based on experiments. The modern atomic theory is that atoms contain a nucleus of protons and neutrons surrounded by electrons in electron clouds, and that elements are defined by their atomic number while isotopes differ in neutron number. The four fundamental forces that act on atoms are also summarized.
This document discusses the four main types of chemical bonds: ionic bonds, covalent bonds, hydrogen bonds, and metallic bonds. Ionic bonds involve the transfer of electrons between atoms. Covalent bonds involve the sharing of electrons between two atoms. Hydrogen bonds are electrostatic attractions between hydrogen atoms covalently bonded to electronegative atoms and another electronegative atom. Metallic bonds are electrostatic attractions between positively charged metal ions and delocalized electrons in metals. Examples of each type of bond are provided.
Genes and DNA molecules carry the genetic code that controls what cells are made of and what they do. DNA is made up of a double helix structure with base pairs that always pair together in the same way - A pairs with T and C pairs with G. DNA can make copies of itself through a process called replication where the DNA helix unzips and each single strand builds a new double strand, allowing genetic information to be passed on to new cells.
Primarily due to polarity, water has remarkable properties that support life. Water molecules are polar, with slightly positive hydrogen atoms and slightly negative oxygen atoms, allowing hydrogen bonds to form between molecules. These bonds give water high surface tension, heat capacity, and solubility, enabling it to dissolve many substances and regulate temperatures essential for organisms.
Water is made of hydrogen and oxygen atoms bonded together in a polar covalent structure. This gives water unique properties including being a universal solvent, having high surface tension, and exhibiting capillary action. Water's polarity allows it to dissolve many other polar substances and gives water high cohesion and adhesion properties. It has a maximum density at 4°C and a high specific heat, meaning it takes a lot of energy to change its temperature. These characteristics are crucial to life and many natural processes.
- 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.
This document discusses key concepts of evolution including the history of evolutionary theories from creationism to modern ideas like punctuated equilibrium. It covers Darwin and Wallace's model of natural selection and how environmental pressures can lead to speciation. The fundamentals of evolution are explained including variation, inheritance, selection over time. The role of tectonic plate movement in genetic isolation and speciation is described. Various forms of evidence for evolution are listed such as the fossil record, present-day examples, and molecular clocks using mitochondrial DNA.
The document discusses the electronic configuration of atoms, which is the arrangement of electrons in an atom's orbitals. It defines the key terms of energy levels and sublevels, which are the orbitals where electrons are arranged. Examples of electronic configurations are given for several elements, such as iodine and silicon. Rules for determining electronic configuration, such as Aufbau's principle, Pauli's exclusion principle, and Hund's rule are also outlined.
The document discusses chemical formulas and how they are used to express information about the proportions of atoms in compounds. It covers:
- Chemical formulas for covalent molecular compounds, covalent networks, and ionic compounds show the number or ratio of elements present
- Formulas are written using element symbols and subscripts to indicate atom counts
- Valence and Roman numerals are used to indicate an element's bonding tendency which helps write formulas
- Prefixes like mono-, di-, tri- are also used to show atom ratios
- Polyatomic ions, ions formed of multiple elements, are also represented in formulas
- Ionic formulas show the charges of ions present in ionic substances
Molecular compounds are formed when two or more different non-metal atoms combine via covalent bonds, sharing electron pairs. Examples include water, which is made of two hydrogen atoms bonded to one oxygen atom. Molecular compounds have properties like being soft and having low melting points. They are named systematically with the first element, the second as an "-ide", and prefixes to indicate atom amounts, like dinitrogen monoxide for N2O.
Chemical bonds form through different types of attractions between atoms. Ionic bonds form when electrons are transferred from one atom to another, creating oppositely charged ions that are attracted to each other. Covalent bonds form when atoms share electrons equally. Ionic bonds are generally stronger than covalent bonds because more energy is required to overcome the electrostatic forces between ions.
5.4 exothermic and endothermic reactionsMartin Brown
This document discusses exothermic and endothermic reactions. Exothermic reactions release heat, while endothermic reactions absorb heat. Combustion reactions of hydrocarbons like methane and propane are exothermic, producing carbon dioxide, water vapor, and large amounts of heat. The heat of reaction, ΔH, indicates whether a reaction is exothermic (negative ΔH) or endothermic (positive ΔH). Bond energies represent the energy required to break bonds, while heat of combustion measures the heat released from complete combustion. A bomb calorimeter is used to accurately measure heats of combustion by igniting samples in excess oxygen. Hess's law states that the heat change of a reaction depends only on
Cellular respiration involves the breakdown of glucose and other organic molecules to extract energy in the form of ATP. It occurs in three main stages: glycolysis, the Krebs cycle in the mitochondria, and oxidative phosphorylation along the electron transport chain. During aerobic respiration, glucose breakdown yields about 38 ATP molecules total. Without oxygen, anaerobic respiration produces less ATP but allows glycolysis to continue by converting pyruvate into other waste products like lactic acid.
This document discusses photosynthesis in plants. It begins by stating the objectives of understanding the structures, raw materials, and products of photosynthesis. It then describes where photosynthesis takes place inside the chloroplasts in plant leaves. The two stages of photosynthesis are explained as the light-dependent reaction which uses light to produce ATP and NADPH, and the light-independent Calvin cycle which uses those products to fix carbon dioxide into glucose in the chloroplast stroma. Key terms involved in the process are also defined.
Chapter 4.2 : The Quantum Model of the AtomChris Foltz
Louis de Broglie proposed that electrons behave as waves, confined to certain regions around the nucleus at specific energy levels, known as orbitals. The Heisenberg Uncertainty Principle states that it is impossible to know both the position and momentum of an electron simultaneously. Schrodinger's wave equation treats electrons as waves and uses the uncertainty principle to describe the probability of finding electrons in certain orbital regions. Quantum numbers specify the properties of orbitals and electrons, including the principal quantum number for energy level, angular momentum quantum number for orbital shape, and magnetic quantum number for orbital orientation.
This document discusses different types of intermolecular forces: dipole-dipole forces between polar molecules, ion-dipole forces between ions and polar molecules, dispersion forces between all molecules due to induced dipoles, and strong hydrogen bonds between partial charges on hydrogen and electronegative atoms like N, O, F. These intermolecular forces are responsible for determining the properties and phase of substances.
The document discusses Lewis dot structures, which use dots to represent valence electrons around an atomic symbol. It explains that ions have Lewis dot diagrams with fewer (for cations) or more (for anions) dots than the corresponding atom due to gaining or losing electrons. The document provides examples of Lewis dot diagrams for various ions, such as Ca2+ and O2-. It also includes practice problems asking students to draw Lewis dot diagrams for additional ions.
The Kinetic Molecular Theory states that all matter is composed of particles in constant motion. It explains the properties of solids, liquids, and gases by proposing five assumptions: 1) gases consist of tiny particles far apart with mostly empty space, 2) collisions are elastic with no energy loss, 3) particles move rapidly and randomly, 4) there are no attractive or repulsive forces between particles, and 5) average kinetic energy depends on temperature. The theory accounts for gas properties like expansion, fluidity, low density, compressibility, and diffusion/effusion.
Chemistry - Chp 9 - Chemical Names and Formulas - PowerPointMel Anthony Pepito
Here are the formulas or names for the given ionic compounds:
1. Iron (II) Phosphate - Fe3(PO4)2
2. Tin (II) Fluoride - SnF2
3. Potassium Sulfide - K2S
4. Ammonium Chromate - (NH4)2CrO4
5. MgSO4 - Magnesium sulfate
6. FeC - Iron (II) carbide
This document outlines the development of atomic theory from ancient Greek philosophers to modern physics. It describes key contributors such as Democritus, Dalton, Thomson, Rutherford, Bohr, and Schrodinger who proposed models of the atom based on experiments. The modern atomic theory is that atoms contain a nucleus of protons and neutrons surrounded by electrons in electron clouds, and that elements are defined by their atomic number while isotopes differ in neutron number. The four fundamental forces that act on atoms are also summarized.
This document discusses the four main types of chemical bonds: ionic bonds, covalent bonds, hydrogen bonds, and metallic bonds. Ionic bonds involve the transfer of electrons between atoms. Covalent bonds involve the sharing of electrons between two atoms. Hydrogen bonds are electrostatic attractions between hydrogen atoms covalently bonded to electronegative atoms and another electronegative atom. Metallic bonds are electrostatic attractions between positively charged metal ions and delocalized electrons in metals. Examples of each type of bond are provided.
Genes and DNA molecules carry the genetic code that controls what cells are made of and what they do. DNA is made up of a double helix structure with base pairs that always pair together in the same way - A pairs with T and C pairs with G. DNA can make copies of itself through a process called replication where the DNA helix unzips and each single strand builds a new double strand, allowing genetic information to be passed on to new cells.
Primarily due to polarity, water has remarkable properties that support life. Water molecules are polar, with slightly positive hydrogen atoms and slightly negative oxygen atoms, allowing hydrogen bonds to form between molecules. These bonds give water high surface tension, heat capacity, and solubility, enabling it to dissolve many substances and regulate temperatures essential for organisms.
Water is made of hydrogen and oxygen atoms bonded together in a polar covalent structure. This gives water unique properties including being a universal solvent, having high surface tension, and exhibiting capillary action. Water's polarity allows it to dissolve many other polar substances and gives water high cohesion and adhesion properties. It has a maximum density at 4°C and a high specific heat, meaning it takes a lot of energy to change its temperature. These characteristics are crucial to life and many natural processes.
properties of water.ppt for grade 9 high schoolOmarSaied7
The document discusses isotopes, radioactive isotopes, and radiometric dating. It defines isotopes as atoms of the same element that vary only in the number of neutrons. Chemically, isotopes of the same element are identical. Some isotopes are radioactive and decay at a known rate called the half-life. Knowing an isotope's half-life enables scientists to accurately date fossils and estimate the age of the Earth using radiometric dating. Radioisotopes also have medical uses like diagnosing and treating thyroid conditions.
Water is essential for life on Earth. It is the most abundant liquid and covers over 70% of the planet. Water is essential for photosynthesis and respiration, the two key reactions that sustain life. It acts as a solvent and transports nutrients, wastes, and heat around organisms. Water's unique properties, including its high heat capacity and ability to form hydrogen bonds, allow it to remain liquid over a wide range of temperatures on Earth. Its polarity allows it to dissolve many other polar substances. Water's hydrogen bonding gives it high melting and boiling points compared to other molecules of similar size.
1. Many of water's unique properties, like its high surface tension and low vapor pressure, result from hydrogen bonding between water molecules.
2. A surfactant can reduce water's surface tension by interfering with these hydrogen bonds.
3. Ice has a lower density than liquid water because the hydrogen bonds in ice form a rigid, open honeycomb structure that expands when it melts.
Water is a polar molecule that readily forms hydrogen bonds between its oxygen and hydrogen atoms. This allows water to act as a versatile solvent and absorb large amounts of heat, properties important for life. Water's hydrogen bonding and polarity enable it to dissolve many other polar substances and ions, making it the universal solvent. Its high heat capacity moderates temperatures and allows living organisms to regulate their internal environments. Water's unique physical properties, including its surface tension and ability to absorb heat, are crucial for biological and ecological functions on Earth.
Explain how water interacts with the following types of compounds to.pdfarmyshoes
Explain how water interacts with the following types of compounds to influence their water
solubility.
1.Compounds that can hydrogen bond
2. Compounds that are polar but cannot hydrogen bond
3. Compounds that are non-polar
4. Compounds that dissociate into cations and anions.
Thank you so much.
Solution
Compounds that can hydrogen bond
Water tends to disassociate into H+ and OH- ions. In this disassociation, the oxygen retains the
electrons and only one of the hydrogens, becoming a negatively charged ion known as
hydroxide. Pure water has the same number (or concentration) of H+ as OH- ions. Acidic
solutions have more H+ ions than OH- ions. Basic solutions have the opposite. An acid causes an
increase in the numbers of H+ ions and a base causes an increase in the numbers of OH- ions.
Water, which not only dissolves many compounds but also dissolves more substances than any
other liquid, is considered the universal solvent. A polar molecule with partially-positive and
negative charges, it readily dissolves ions and polar molecules. Water is therefore referred to as a
solvent: a substance capable of dissolving other polar molecules and ionic compounds.
The charges associated with these molecules form hydrogen bonds with water, surrounding the
particle with water molecules. This is referred to as a sphere of hydration, or a hydration shell,
and serves to keep the particles separated or dispersed in the water.
Compounds that dissociate into cations and anions.-When ionic compounds are added to water,
individual ions interact with the polar regions of the water molecules during the dissociation
process, disrupting their ionic bonds. Dissociation occurs when atoms or groups of atoms break
off from molecules and form ions. Consider table salt (NaCl, or sodium chloride): when NaCl
crystals are added to water, the molecules of NaCl dissociate into Na+ and Cl– ions, and spheres
of hydration form around the ions. The positively-charged sodium ion is surrounded by the
partially-negative charge of the water molecule\'s oxygen; the negatively-charged chloride ion is
surrounded by the partially-positive charge of the hydrogen in the water molecule.
Compounds that are polar and non-polar-
-Since many biomolecules are either polar or charged, water readily dissolves these hydrophilic
compounds. Water is a poor solvent, however, for hydrophobic molecules such as lipids.
Nonpolar molecules experience hydrophobic interactions in water: the water changes its
hydrogen bonding patterns around the hydrophobic molecules to produce a cage-like structure
called a clathrate. This change in the hydrogen-bonding pattern of the water solvent causes the
system\'s overall entropy to greatly decrease, as the molecules become more ordered than in
liquid water. Thermodynamically, such a large decrease in entropy is not spontaneous, and the
hydrophobic molecule will not dissolve.
-Polar substances tend to dissolve well in other polar substances, but not nonpolar substances,
whil.
Water has unique properties due to its molecular structure as a polar covalent molecule. It can form hydrogen bonds between molecules which allow it to absorb large amounts of heat as it changes phases and gives it high surface tension and ability to dissolve many solutes. These hydrogen bonds are what allow water to have unusual properties like floating ice and temperature moderation.
Water's unique properties are due to its polar nature and ability to form hydrogen bonds between molecules. This allows water to have high cohesive and adhesive forces, giving it properties like surface tension and capillary action. Its polarity also allows water to be an excellent solvent. Water has a high specific heat capacity and heat of vaporization due to the energy required to break hydrogen bonds, giving it high thermal buffering abilities. Substances can be hydrophilic (water-loving) if polar or ionic, allowing dissolution, or hydrophobic. In the body, glucose and ions are water soluble and transported in blood plasma, while fats and gases require transport via other mechanisms due to low solubility. Water's properties make it perfectly
The ability of water to form hydrogen bonds gives it amazing properties including: ability to dissolve hydrophilic (ionic and polar) but not hydrophobic (nonionic, nonpolar) molecules so as to be the "universal solvent," liquid state over large earthly temperature range, high heats of fusion and vaporization, high specific heat, high surface tension, cohesion and adhesion, lower density as solid, low viscosity, equal ionization into proton donor and acceptor for neutral pH. These properties make life on earth possible
The document discusses several key properties of water that support life, including:
1) Water is a polar molecule that forms hydrogen bonds between molecules, giving it properties like cohesion, surface tension, and the ability to moderate temperature.
2) The polarity and hydrogen bonding of water allow it to be an excellent solvent for dissolving many polar and ionic substances.
3) Ice floats on water because it has a lower density than liquid water, which prevents bodies of water from freezing solid.
Water is the most abundant substance on Earth's surface, exists as a liquid, solid, and gas, and has many unique properties. It has high values for melting point, heat of fusion, boiling point, heat of vaporization, specific heat, and surface tension compared to other solvents. These properties allow water to absorb large amounts of heat while resisting changes in state, helping to moderate Earth's climate. The density of water is highest at 4°C and lowest as ice, allowing ice to float in liquid water. Hydrogen bonding between water molecules gives water its cohesive and adhesive properties that are important for life.
This document provides an overview of biochemistry by discussing the properties of water and its importance for life. It notes that water is a polar molecule that can form hydrogen bonds, giving it unique properties like high heat capacity and surface tension. These hydrogen bonds allow water to dissolve many polar substances. Water's hydrogen bonding and ability to dissolve biomolecules make it essential as the universal solvent for living organisms. The document also briefly discusses solutions, solutes, solvents, and how water interacts with charged and nonpolar compounds.
Water is a polar molecule that forms hydrogen bonds between other water molecules. This gives water unusual properties like being a universal solvent, having high surface tension and heat of vaporization. The hydrogen bonds allow water molecules to bond together through cohesion and adhesion, enabling plants to transport water against gravity. Water's density also prevents freezing from the bottom up, making environments more stable for aquatic organisms.
The document provides information about the properties of water. It begins by explaining the structure of the water molecule as made up of one oxygen atom and two hydrogen atoms in a bent shape. It then discusses seven key properties of water: 1) Polarity 2) Capillary action 3) Surface tension 4) Heat capacity 5) Heat of vaporization 6) Density 7) Being a universal solvent. For each property it provides details on how it arises from the molecular structure of water and demonstrations of the properties.
Water is essential for life processes due to its unique properties. It is highly polar and can dissolve many other polar molecules and ions, allowing important chemical reactions to take place in living things. Water regulates temperature via hydrogen bonding, which allows it to absorb large amounts of heat with only small temperature changes. It also has a high heat of vaporization, enabling organisms to cool down through sweating and evaporation. The polarity and hydrogen bonding of water gives it cohesive properties like surface tension and a high heat capacity, making it well-suited as a solvent and temperature regulator for Earth's diverse organisms.
4043247.ppt biochemistry of water & electrolyteAnnaKhurshid
This document provides an overview of key concepts regarding water and its importance in biochemistry. It discusses water's unique physical and chemical properties, including its molecular structure and ability to form hydrogen bonds. This allows water to have high boiling and melting points and act as a universal solvent. The document also covers water's roles as a solvent, including hydrophilic and hydrophobic interactions. It describes noncovalent bonds like ionic interactions, hydrogen bonds, and van der Waals forces that are important for molecular interactions in water. Key properties of water like its thermal properties, osmotic pressure, and role in acid-base reactions are also summarized.
Inorganic molecules are compounds that don't contain carbon and hydrogen together. Important inorganic compounds for living organisms include water, oxygen, carbon dioxide, nitrogen, and minerals. Water is the most abundant compound in organisms and is the predominant solvent due to its cohesive and adhesive properties, which allow it to dissolve other polar substances and transport materials via capillary action and surface tension.
1. Water is a polar molecule made up of oxygen and hydrogen atoms, with the oxygen side having a slight negative charge and the hydrogen sides having a slight positive charge.
2. This polarity allows water molecules to form hydrogen bonds with other water molecules, giving water its unique properties. Water is able to dissolve many other polar substances for this reason.
3. The hydrogen bonding between water molecules also gives water properties like high surface tension and the ability to exist as a liquid at temperatures higher than zero degrees Celsius. This hydrogen bonding is important for life.
Water is essential for life processes due to its polarity and ability to dissolve many substances. The polarity of the water molecule, with oxygen more electronegative than hydrogen, allows it to dissolve both polar and ionic compounds. This polarity also gives water high specific heat and heat of vaporization, enabling it to stabilize temperatures. Water's hydrogen bonding gives it cohesion, surface tension, and the ability to absorb large amounts of heat with only small temperature changes.
Similar to Chapter 15 water and aqueous systems (20)
Attendance is strongly correlated with academic achievement and graduation rates. Students who miss school frequently are more likely to have lower test scores and drop out of high school. Dropping out is usually a gradual process that begins with disengagement from school as early as first grade. The three main factors influencing a student's decision to drop out are academic failure, social and economic issues, and lack of adult guidance. Poor attendance, grades, failure to be promoted, and classroom disengagement are key indicators that a student may drop out, and these signs can be identified as early as sixth grade. Schools should closely monitor attendance, especially for ninth graders, in the first month of school as missing just 10 days or more in the first
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1. Chapter 15 “Water and Aqueous Systems”
Pre-AP Chemistry
Charles Page High School
Stephen L. Cotton
2. Section 15.1
Water and it’s Properties
OBJECTIVES:
–Explain the high surface
tension and low vapor
pressure of water in terms of
the structure of the water
molecule and hydrogen
bonding.
3. Section 15.1
Water and it’s Properties
OBJECTIVES:
–Describe the structure of
ice.
4. The Water Molecule: a Review
Water is a simple tri-atomic molecule, H2O
Each O-H bond is highly polar,
because of the high electronegativity of
the oxygen (N, O, F, and Cl have high values)
bond angle of water = 105o
due to the bent shape, the O-H bond
polarities do not cancel. This means:
water is a polar molecule.
5. The Water Molecule: a Review
δ is the lowercase Greek symbol delta
δ+ means a
Thus, water has a δ- means a
partial
partial negative end partial
positive
(0xygen) and a negative
charge
partial positive end δ- charge
(Hydrogen), and it O
is called “polar” H H
because of these
δ+ δ+
areas of difference
6. The Water Molecule
Water’s
bent shape and ability to
hydrogen bond gives it many
special properties!
What was hydrogen bonding?
Water molecules are attracted to one
another by dipole interactions – p. 446
This hydrogen bonding gives water:
a) its high surface tension, and
b) its low vapor pressure.
7. a) High Surface Tension?
liquidwater acts like it has a “skin”
–glass of water bulges over the top
Water forms round drops
–spray water on greasy surface
All because water hydrogen bonds.
Fig. 15.4, p.447 – how does this
insect walk on the water? (see next slide)
9. Surface Tension
One water molecule -
can hydrogen bond to
another because of
+ H +
this electrostatic
attraction.
Also, hydrogen -
bonding occurs with
many other molecules H
+ +
surrounding them on
all sides.
11. Surface Tension
Not true at the surface.
They are pulled down
and to each side, not
upward since the water
and air are not attracted
to each other.
This holds the
molecules at the
surface together tightly.
This causes surface
tension.
12. Surface Tension
Water drops are
rounded, because
all molecules on
the edge are pulled
to the middle, not
outward to the air!
A drop has the
least amount of
surface area for
any given volume.
13. Surface Tension
Glass has polar
molecules.
Glass can also
hydrogen bond.
This attracts the
water molecules.
Some of them
are pulled up a
cylinder wall.
14. Meniscus
A meniscus is the curved surface at the top of a column of liquid.
Thus, water curves up
along the sides of glass.
This makes the
meniscus, as in a
graduated cylinder
However, Plastics are
non-wetting; there is no
attraction to water
15. Meniscus
Water is attracted to Water not attracted to
the Glass, thus Plastic, but to other
curves up the sides water molecules
16. Surface tension
All liquids have surface tension
–water is just higher than most others,
due to the hydrogen bonding present
How can we decrease surface tension?
–Use a surfactant - surface active
agent
–Also called a “wetting agent”, like
detergent or soap (makes water “wetter”)
–Interferes with hydrogen bonding
17. b) Low vapor pressure?
• Hydrogen bonding also explains water’s
unusually low vapor pressure.
–It holds water molecules together, so
they do not escape (evaporate)
easily, like gasoline or acetone does.
–This is a good thing, because lakes
and oceans would evaporate very
quickly due to their large surface
area!
18. Ice
Most liquids contract (get smaller) as they
are cooled.
–They get more dense.
When they change to solid, they are
more dense than the liquid.
Solid metals sink in their own liquid metal.
–But, ice floats in water.
Why?
19. Ice
Water becomes more dense as it cools,
until it reaches about 4ºC.
– Then it becomes less dense by starting
to expand (Want your water pipes to freeze in the winter?)
Because as the molecules slow down,
they arrange themselves into honeycomb-
shaped crystals.
These are held together by hydrogen
bonds. Fig. 15.5, p.449
20. Liquid = random shaped Solid = honeycomb-
arrangement shaped arrangement
O
21. Ice
Is10% lower in density than liquid water.
Water freezes from the top down.
–The layer of ice on a pond acts as an
insulator for water below
Why is ice less dense than liquid water?
–The structure of ice is a regular open
framework of water molecules,
arranged like a honeycomb.
22. Ice
A considerable amount of energy is
required to return water in the solid
state to the liquid (called melting)
–The heat absorbed when 1 g of water
changes from solid to liquid is 334 J.
–This is the same amount of energy
needed to raise the temperature of 1
g of liquid water from 0 oC to 80 oC!
23. Section 15.2 Homogeneous
Aqueous Solutions
OBJECTIVES:
–Distinguish between a
solvent and a solute.
24. Section 15.2 Homogeneous
Aqueous Solutions
OBJECTIVES:
–Describe what happens
in the solution process.
25. Section 15.2 Homogeneous
Aqueous Solutions
OBJECTIVES:
–Explain why all ionic
compounds are known
as electrolytes.
26. Section 15.2 Homogeneous
Aqueous Solutions
OBJECTIVES:
–Demonstrate how the
formula for a hydrate is
written.
27. Solvents and Solutes
Solution - a homogenous mixture, that is
mixed molecule by molecule; made of:
1) a Solvent - the dissolving medium
2) a Solute - the dissolved particles
Aqueous solution- a solution with water
as the solvent.
Particle size is less than 1 nm; cannot be
separated by filtration – Fig. 15.6, p.450
28. Parts of a Solution:
1. the Solute
A solute is the dissolved substance in a
solution.
Salt in salt water Sugar in soda drinks
Carbon dioxide in soda drinks
2. the Solvent
A solvent is the dissolving medium in a
solution.
Water in salt water Water in soda
29. Solutions
Keep in mind that solutions do
not have to contain water, but
this is the type we are studying in
this chapter = aqueous solutions
–Example: air and jewelry are
also types of solutions.
31. Concentrated vs. Dilute
Concentrated vs. Dilute
Lots of solute, but Lots of solvent,
little solvent but little solute
32. Aqueous Solutions
Water dissolves ionic compounds and
polar covalent molecules very well.
The rule is: “like dissolves like”
Polar dissolves polar.
Nonpolar dissolves nonpolar.
Oil is nonpolar.
– Oil and water don’t mix.
Salt is ionic- makes salt water.
33. The Solution Process
Called “solvation”.
Water 1) breaks the + and - charged
pieces apart, and 2) surrounds them.
Fig. 15.7, p. 451
But, in some ionic compounds, the
attraction between ions is greater than
the attraction exerted by water
– Barium sulfate and calcium carbonate do
not dissolve in water!
34. How Ionic solids dissolve in water
These ions have been pulled away from the
main crystal structure by water’s polarity.
H
H
H
H H
These ions have been
surrounded by water,
and are now dissolved!
35. Solids will dissolve if the attractive force of
the water molecules is stronger than the
attractive force of the crystal.
If not, the solids are insoluble.
Water doesn’t dissolve nonpolar molecules
(like oil) because the water molecules can’t
hold onto them.
The water molecules hold onto other water
molecules, and separate from the nonpolar
molecules.
Nonpolars? No repulsion between them
36. Electrolytes and Nonelectrolytes
Electrolytes- compounds that conduct
an electric current in aqueous solution,
or in the molten state
–all ionic compounds are electrolytes
because they dissociate into ions
(they are also called “salts”)
barium sulfate- will conduct when
molten, but is insoluble in water!
37. Electrolytes and Nonelectrolytes
Do not conduct? = Nonelectrolytes.
–Most are molecular materials,
because they do not have ions
Not all electrolytes conduct to the same
degree
–there are weak electrolytes, and
strong electrolytes
–depends on: the degree of ionization
38. Electrolytes vs. Nonelectrolytes
The ammeter measures the flow of electrons (current) through the circuit.
If the ammeter measures a current and the
bulb glows, then the solution conducts.
If the ammeter fails to measure a current and the bulb
does not glow, the solution is non-conducting.
39. Electrolytes and Nonelectrolytes
Strong electrolytes exist as nearly
100 % ions
Weak electrolytes have only a
fraction of the solute that exists as
ions
How do you know if it is strong or
weak? Refer to the rules on the
handout sheet.
40. Electrolyte Summary
Substances that conduct electricity when
dissolved in water, or molten.
Must have charged particles that can
move.
Ionic compounds break into charged ions:
NaCl Na1+ and Cl1-
These ions can conduct electricity.
41. Nonelectrolytes do not conduct
electricity when dissolved in water or
molten
Polar covalent molecules such as
methanol (CH3OH) don’t fall apart into
ions when they dissolve.
Weak electrolytes don’t fall completely
apart into ions.
Strong electrolytes do ionize
completely.
42. Water of Hydration
(or Water of Crystallization)
Water molecules are chemically bonded
to solid salt molecules (not in solution)
These compounds have fixed amounts
of water.
The water can be driven off by heating:
Hydrate Anhydrous
+ heat
.
CuSO4 5H2O CuSO4 +
- heat
5H2O
Called copper(II)sulfate pentahydrate.
43. Hydrates
Table 15.2, p.455 list some familiar
hydrates
Since heat can drive off the water, the
forces holding the water are weak
If a hydrate has a vapor pressure
higher than that of water vapor in air,
the hydrate will effloresce by losing
the water of hydration
44. Hydrates
Some hydrates that have a low vapor
pressure remove water from the air to
form higher hydrates- these are called
hygroscopic
–used as drying agents, or dessicants
–packaged with products to absorb
moisture
46. Hydrates
Some compounds are so
hygroscopic, they become wet
when exposed to normally moist
air - called deliquescent
–remove sufficient water to
dissolve completely and form
solutions: Fig. 15.13, page 457
49. Mixtures that are NOT Solutions:
1. Suspensions: mixtures that slowly settle
upon standing. Example: sand in water
–Particles of a suspension are greater in
diameter than 1000 nm.
–Can be separated by filtering (p.459)
2. Colloids: heterogeneous mixtures with
particles between the size of suspensions
and true solutions (1-1000 nm)
50. Mixtures that are NOT Solutions
The colloid particles are the dispersed
phase, and are spread throughout the
dispersion medium
The first colloids were glues. Others
include mixtures such as gelatin, paint,
aerosol sprays, and smoke
Table 15.3, p.460 (next slide) lists some
common colloidal systems and
examples
52. Mixtures that are NOT Solutions
Many colloids are cloudy or milky in
appearance when concentrated, but
almost clear when dilute
–They do not settle out
–They can not be filtered out
Colloids exhibit the Tyndall effect - the
scattering of visible light in all directions.
–suspensions also show Tyndall effect
53. Colloids and
suspensions The Tyndall Effect
scatter light,
making a beam You can see Here you cannot
visible, due to the light beam see the light
because the beam; particles
their large large particles are too small to
particle size. reflect the reflect light
light
Solutions do not
scatter light,
because of their colloid solution
small particle size. Which glass contains a colloid?
Should you drive in fog with your high beams on? Why?
54. - Page 461
Note that you can easily see the “sunbeams”, probably due
to the presence of fog (a colloid) in the forest reflecting light
55. Mixtures that are NOT Solutions
Flashes of light are seen when colloids
are studied under a microscope- light is
reflecting- called Brownian motion to
describe the chaotic movement of the
particles. Observed by Robert Brown.
Table 15.4, p.462 (next slide) will
summarize the properties of solutions,
colloids, and suspensions
57. Mixtures that are NOT Solutions
Emulsions- dispersions of a liquid in a liquid (2
immiscible liquids + an emulsifier)
– an emulsifying agent is essential for
maintaining stability; it has one polar end, and
the other end is nonpolar
– oil and water not soluble; but with soap or
detergent added, they will be.
Oil + vinegar in dressing – are they soluble?
– What makes up Mayonnaise? (page 462)
– What makes up Margarine?
58. Distillation equipment – Exp. #26
(Distillation works because of differences in boiling points)
The condenser has cool water that
turns the vapors back into liquid
The “distillate” is then
collected as a liquid.
Chemicals
are heated,
and those
that boil
first will
escape as
vapor