chemistry 112 overview of chapters 1-4. chapter 1 highlights chemistry is the study of matter, the...
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Chemistry 112Chemistry 112
Overview of Chapters 1-4Overview of Chapters 1-4
Chapter 1 HighlightsChapter 1 Highlights
Chemistry is the study of matter, the physical substance of all materials.
The building blocks of matter are atoms, which combine to form compounds.
The different types of atoms are called elements, which are arranged systematically in the periodic table.
Chemistry is the study of matter, the physical substance of all materials.
The building blocks of matter are atoms, which combine to form compounds.
The different types of atoms are called elements, which are arranged systematically in the periodic table.
Atoms are composed of protons, neutrons, and electrons.
All atoms of the same element contain the same number of protons (and electrons) but may vary in the number of neutrons.
The protons and neutrons are found inside the tiny but dense nucleus, whereas the electrons are found in orbitals outside the nucleus.
Atoms are composed of protons, neutrons, and electrons.
All atoms of the same element contain the same number of protons (and electrons) but may vary in the number of neutrons.
The protons and neutrons are found inside the tiny but dense nucleus, whereas the electrons are found in orbitals outside the nucleus.
Chapter 1 Highlights (cont)
Chapter 1 Highlights (cont)
The arrangement of electrons in the orbitals is called the electronic configuration and determines the chemistry of an atom.
The arrangement of electrons in the orbitals is called the electronic configuration and determines the chemistry of an atom.
Chapter 1 Highlights (cont)
Chapter 1 Highlights (cont)
Types of Matter Types of Matter
States of MatterStates of Matter
Chemistry and Matter Physical Changes versus Chemical
Changes Physical changes involve changes in
appearance (i.e., changes in state such as melting).
Chemical changes result in new substances.
Chemistry and Matter Physical Changes versus Chemical
Changes Physical changes involve changes in
appearance (i.e., changes in state such as melting).
Chemical changes result in new substances.
The Building Blocks of Matter Atoms
Smallest representative units of the elements.
Compounds Different atoms linked together; e.g., H2O.
The Building Blocks of Matter Atoms
Smallest representative units of the elements.
Compounds Different atoms linked together; e.g., H2O.
The Building Blocks of Matter (cont) Dalton’s Atomic Theory
All matter is composed of indivisible atoms. All atoms of one element are identical to each
other but different than the atoms of other elements.
Compounds are formed when atoms of different elements combine in whole number ratios.
Atoms are rearranged during chemical reactions but atoms cannot be created or destroyed.
The Building Blocks of Matter (cont) Dalton’s Atomic Theory
All matter is composed of indivisible atoms. All atoms of one element are identical to each
other but different than the atoms of other elements.
Compounds are formed when atoms of different elements combine in whole number ratios.
Atoms are rearranged during chemical reactions but atoms cannot be created or destroyed.
The Periodic Table Used to organize the elements by
recurring chemical properties. Elements in the same vertical column of
the periodic table have similar chemical properties and are said to be in the same group or family.
The Periodic Table Used to organize the elements by
recurring chemical properties. Elements in the same vertical column of
the periodic table have similar chemical properties and are said to be in the same group or family.
The Periodic Table The Periodic Table
The Atom Components
Positive protons, negative electrons, and neutral neutrons
Atomic Number The number of protons in an atom,
which determines what element it is Mass Number
Number of protons + the number of neutrons
The Atom Components
Positive protons, negative electrons, and neutral neutrons
Atomic Number The number of protons in an atom,
which determines what element it is Mass Number
Number of protons + the number of neutrons
The Atom (cont) Isotopes
Isotopes of the same element have the same number of protons but differ in the number of neutrons.
Atomic Mass The atomic mass for each element
on the periodic table reflects the relative abundance of each isotope in nature.
The Atom (cont) Isotopes
Isotopes of the same element have the same number of protons but differ in the number of neutrons.
Atomic Mass The atomic mass for each element
on the periodic table reflects the relative abundance of each isotope in nature.
IsotopesIsotopes
Models of the Atom The Plum Pudding Model
Electrons are embedded in a sphere of positive charge.
The Nuclear Model All of the positive charge is in a tiny central
nucleus with electrons outside the nucleus. This model was developed by Rutherford
after his landmark experiment.
Models of the Atom The Plum Pudding Model
Electrons are embedded in a sphere of positive charge.
The Nuclear Model All of the positive charge is in a tiny central
nucleus with electrons outside the nucleus. This model was developed by Rutherford
after his landmark experiment.
The Rutherford Experiment
The Rutherford Experiment
Models of the Atom (continued) Bohr’s Solar System Model
Electrons circle the nucleus in orbits, which are also called energy levels.
An electron can “jump” from a lower energy level to a higher one upon absorbing energy, creating an excited state.
The concept of energy levels accounts for the emission of distinct wavelengths of electromagnetic radiation during flame tests.
Models of the Atom (continued) Bohr’s Solar System Model
Electrons circle the nucleus in orbits, which are also called energy levels.
An electron can “jump” from a lower energy level to a higher one upon absorbing energy, creating an excited state.
The concept of energy levels accounts for the emission of distinct wavelengths of electromagnetic radiation during flame tests.
The Solar System ModelThe Solar System Model
Electromagnetic RadiationElectromagnetic Radiation
Models of the Atom (continued) The Modern Model
Orbits are replaced with orbitals, volumes of space where the electrons can be found.
The arrangement of electrons in the orbitals is the electronic configuration of an atom, which determines the chemistry of an atom.
Models of the Atom (continued) The Modern Model
Orbits are replaced with orbitals, volumes of space where the electrons can be found.
The arrangement of electrons in the orbitals is the electronic configuration of an atom, which determines the chemistry of an atom.
The Orbital Model:Electronic Configurations
The Orbital Model:Electronic Configurations
Chapter 2 HighlightsChapter 2 Highlights
Having eight valence electrons is particularly desirable (“the octet rule”).
Atoms form bonds with other atoms to satisfy the octet rule.
The two major types of chemical bonds are ionic and covalent.
Having eight valence electrons is particularly desirable (“the octet rule”).
Atoms form bonds with other atoms to satisfy the octet rule.
The two major types of chemical bonds are ionic and covalent.
Electronegativity is the ability to attract shared electrons.
The type of bond formed between two atoms depends on their difference in electronegativity.
Ionic bonds form between atoms with a large difference in electronegativity (generally a metal and a nonmetal).
Electronegativity is the ability to attract shared electrons.
The type of bond formed between two atoms depends on their difference in electronegativity.
Ionic bonds form between atoms with a large difference in electronegativity (generally a metal and a nonmetal).
Chapter 2 Highlights (cont)
Chapter 2 Highlights (cont)
Nonpolar covalent bonds form between atoms with little difference in electronegativity (generally two nonmetals).
Polar covalent bonds form between atoms with intermediate difference in electronegativity.
There are many ways to depict molecules.
Nonpolar covalent bonds form between atoms with little difference in electronegativity (generally two nonmetals).
Polar covalent bonds form between atoms with intermediate difference in electronegativity.
There are many ways to depict molecules.
Chapter 2 Highlights (cont)
Chapter 2 Highlights (cont)
The Octet Rule Atoms with eight valence electrons
are particularly stable, an observation called the octet rule.
Atoms form bonds with other atoms to achieve a valence octet.
The Octet Rule Atoms with eight valence electrons
are particularly stable, an observation called the octet rule.
Atoms form bonds with other atoms to achieve a valence octet.
ElectronicConfiguration of Noble
Gases
ElectronicConfiguration of Noble
Gases
Types of Compounds Types of Compounds
Lewis Dot StructuresLewis Dot Structures
Ionic Bonds Ionic compounds result from the loss
of electrons by one atom (usually a metal) and the gain of electrons by another atom (usually a nonmetal).
Ionic bonds arise from the attraction between particles with opposite charges (electrostatic forces); e.g., Na+ Cl-.
Ionic Bonds Ionic compounds result from the loss
of electrons by one atom (usually a metal) and the gain of electrons by another atom (usually a nonmetal).
Ionic bonds arise from the attraction between particles with opposite charges (electrostatic forces); e.g., Na+ Cl-.
Ionic CompoundsIonic Compounds
Covalent Bonds Covalent bonds are formed when
two atoms share one or more electron pairs.
When two atoms share one pair of electrons, the result is a single bond.
Two shared pairs of electrons is a double bond; three is a triple bond.
Covalent Bonds Covalent bonds are formed when
two atoms share one or more electron pairs.
When two atoms share one pair of electrons, the result is a single bond.
Two shared pairs of electrons is a double bond; three is a triple bond.
Equal Sharing versus Unequal Sharing When two different kinds of atoms are
bonded, the electrons are usually shared unequally.
When a bond exists between two identical kinds of atoms, the electrons are shared equally.
An atom with greater electronegativity has a greater ability to attract shared electrons.
Equal Sharing versus Unequal Sharing When two different kinds of atoms are
bonded, the electrons are usually shared unequally.
When a bond exists between two identical kinds of atoms, the electrons are shared equally.
An atom with greater electronegativity has a greater ability to attract shared electrons.
ElectronegativityElectronegativity
Polar vs. Nonpolar BondsPolar vs. Nonpolar Bonds
Representing Structures In a structural formula, atoms are
represented by chemical symbols, and bonds are represented by lines.
In a line drawing, any point where lines connect or terminate is understood to be a carbon atom with sufficient bonded hydrogen atoms to achieve the four bonds necessary for carbon.
Representing Structures In a structural formula, atoms are
represented by chemical symbols, and bonds are represented by lines.
In a line drawing, any point where lines connect or terminate is understood to be a carbon atom with sufficient bonded hydrogen atoms to achieve the four bonds necessary for carbon.
Drawing MoleculesDrawing Molecules
Chapter 3 HighlightsChapter 3 Highlights
Reaction equations have with the initial materials (reactants) on the left, followed by a reaction arrow pointing from left to right, and the final materials (products) on the right.
A balanced equation has the same number and kinds of atoms on both sides of the equation.
Reaction equations have with the initial materials (reactants) on the left, followed by a reaction arrow pointing from left to right, and the final materials (products) on the right.
A balanced equation has the same number and kinds of atoms on both sides of the equation.
The relationship between the amounts of reactants and products is the stoichiometry, which comes from a balanced reaction equation.
The SI unit for measuring atoms and molecules is the mole.
In an oxidation-reduction reaction, electrons are transferred from one material (the substance that is oxidized) to another material (the substance that is reduced).
The relationship between the amounts of reactants and products is the stoichiometry, which comes from a balanced reaction equation.
The SI unit for measuring atoms and molecules is the mole.
In an oxidation-reduction reaction, electrons are transferred from one material (the substance that is oxidized) to another material (the substance that is reduced).
Chapter 3 HighlightsChapter 3 Highlights
Balanced Reaction Equations Writing a Chemical Reaction
The starting materials, the reactants, are written on the left.
The materials that are produced, the products, are written on the right.
Reactants are separated from products by a horizontal arrow pointing from left to right.
Balanced Reaction Equations Writing a Chemical Reaction
The starting materials, the reactants, are written on the left.
The materials that are produced, the products, are written on the right.
Reactants are separated from products by a horizontal arrow pointing from left to right. Na + Cl NaCl
Reactants Product
Balanced Reaction Equations (cont) Balancing the Equation
The law of conservation of matter states that matter can neither be created nor destroyed in a chemical reaction.
The number and kind of atoms on the left-hand side of an equation must be equal to the number and kind of atoms on the right.
Balanced Reaction Equations (cont) Balancing the Equation
The law of conservation of matter states that matter can neither be created nor destroyed in a chemical reaction.
The number and kind of atoms on the left-hand side of an equation must be equal to the number and kind of atoms on the right.H2 + O2 H2O Incorrect
2 H2 + O2 2 H2O Correct
Balanced Reaction Equations (cont) Stoichiometry
The stoichiometry of a chemical reaction is the relationship between the number of molecules of the reactants and products in the balanced reaction equation.
A reactant present in insufficient amounts is the limiting reagent.
Balanced Reaction Equations (cont) Stoichiometry
The stoichiometry of a chemical reaction is the relationship between the number of molecules of the reactants and products in the balanced reaction equation.
A reactant present in insufficient amounts is the limiting reagent.
The Mole The mole is the SI unit of measure to
describe the amount of matter that is present.
One mole is equal to 6.02 x 1023 particles (Avogadro’s number).
One mole of an element has a mass that is equal to the atomic mass of that element in grams.
One mole of a compound has a mass that is equal to the molecular/formula mass of that compound in grams.
The Mole The mole is the SI unit of measure to
describe the amount of matter that is present.
One mole is equal to 6.02 x 1023 particles (Avogadro’s number).
One mole of an element has a mass that is equal to the atomic mass of that element in grams.
One mole of a compound has a mass that is equal to the molecular/formula mass of that compound in grams.
The Mole The Mole
Stoichiometry Calculations The units of molar mass are
grams/mole. Moles x molar mass = mass.
Example: 2.0 mol CO2 x 44 g/mol = 88 g CO2
Mass/molar mass= moles. Example: 132 g CO2 / 44 g/mol = 3.0 mol CO2
Stoichiometry Calculations The units of molar mass are
grams/mole. Moles x molar mass = mass.
Example: 2.0 mol CO2 x 44 g/mol = 88 g CO2
Mass/molar mass= moles. Example: 132 g CO2 / 44 g/mol = 3.0 mol CO2
Stoichiometry Calculations The expected mass of a product or
reactant can be calculated for any reaction by using the balanced equation and the molar mass.
Stoichiometry Calculations The expected mass of a product or
reactant can be calculated for any reaction by using the balanced equation and the molar mass.
Oxidation-Reduction Reactions Defined
Oxidation-reduction (“redox”) reactions involve the transfer of electrons from one substance to another.
Oxidized substances lose electrons and reduced substances gain electrons.
Oxidation-Reduction Reactions Defined
Oxidation-reduction (“redox”) reactions involve the transfer of electrons from one substance to another.
Oxidized substances lose electrons and reduced substances gain electrons.
Oxidation-ReductionOxidation-Reduction
Oxidation-Reduction Reactions (cont) The Chemistry of Batteries
Combining a readily oxidized substance with an easily reduced substance can create a battery.
The oxidized material is the anode and the reduced material is the cathode of the battery.
Oxidation-Reduction Reactions (cont) The Chemistry of Batteries
Combining a readily oxidized substance with an easily reduced substance can create a battery.
The oxidized material is the anode and the reduced material is the cathode of the battery.
BatteriesBatteries
Chapter 4 HighlightsChapter 4 Highlights
Intermolecular forces hold the molecules of a material together.
Stronger intermolecular forces lead to higher melting and boiling temperatures.
The relative strengths of intermolecular forces generally follow the trend:
hydrogen bonds > dipole-dipole interactions > London forces
Intermolecular forces hold the molecules of a material together.
Stronger intermolecular forces lead to higher melting and boiling temperatures.
The relative strengths of intermolecular forces generally follow the trend:
hydrogen bonds > dipole-dipole interactions > London forces
Like dissolves like. That is, polar solutes dissolve in polar solvents.
Acids are proton (H+) donors; bases are proton acceptors that produce OH- in solution.
The pH measures the acidity of a solution: pH < 7.0 is acidic; pH > 7.0 is basic; pH = 7.0 is neutral.
Acids react with bases in neutralization reactions.
Like dissolves like. That is, polar solutes dissolve in polar solvents.
Acids are proton (H+) donors; bases are proton acceptors that produce OH- in solution.
The pH measures the acidity of a solution: pH < 7.0 is acidic; pH > 7.0 is basic; pH = 7.0 is neutral.
Acids react with bases in neutralization reactions.
Chapter 4 Highlights (cont)
Chapter 4 Highlights (cont)
States of Matter Review of Types of Bonds
1.Chemical bonds (intramolecular forces) hold atoms together.
2.The three types of chemical bonds are ionic, polar covalent, and nonpolar covalent.
3.Intermolecular forces hold molecules together.
States of Matter Review of Types of Bonds
1.Chemical bonds (intramolecular forces) hold atoms together.
2.The three types of chemical bonds are ionic, polar covalent, and nonpolar covalent.
3.Intermolecular forces hold molecules together.
Review of Types of BondsReview of Types of Bonds
Chapter OutlineChapter Outline
States of Matter (cont) Particle Cohesion Determines Physical
State In general, the relative strengths of
intermolecular forces follows the trend: gases < liquids < solids
Changes of State Adding energy breaks intermolecular forces
and causes molecules to change their state. The stronger the intermolecular forces of a
compound, the higher are the melting and boiling points.
States of Matter (cont) Particle Cohesion Determines Physical
State In general, the relative strengths of
intermolecular forces follows the trend: gases < liquids < solids
Changes of State Adding energy breaks intermolecular forces
and causes molecules to change their state. The stronger the intermolecular forces of a
compound, the higher are the melting and boiling points.
Changes of StateChanges of State
Types of Intermolecular Forces within Pure Substances London dispersion forces
A temporary dipole in one molecule can induce a dipole in a neighboring molecule.
The negative end of one temporary dipole can attract the positive end of an induced dipole; these attractions are called London dispersion forces.
London forces tend to be fairly weak.
Types of Intermolecular Forces within Pure Substances London dispersion forces
A temporary dipole in one molecule can induce a dipole in a neighboring molecule.
The negative end of one temporary dipole can attract the positive end of an induced dipole; these attractions are called London dispersion forces.
London forces tend to be fairly weak.
London Dispersion Forces London Dispersion Forces
Types of Intermolecular Forces within Pure Substances (cont) Dipole-dipole interactions
Dipole-dipole interactions exist between molecules with polar covalent bonds.
Dipole-dipole interactions are typically stronger than London dispersion forces.
Types of Intermolecular Forces within Pure Substances (cont) Dipole-dipole interactions
Dipole-dipole interactions exist between molecules with polar covalent bonds.
Dipole-dipole interactions are typically stronger than London dispersion forces.
Dipole-Dipole Interactions Dipole-Dipole Interactions
Types of Intermolecular Forces within Pure Substances (cont) Hydrogen Bonds
Hydrogen bonds are a special type of dipole-dipole interaction.
Hydrogen bonds can occur when H is bonded to one of the highly electronegative atoms N, O, or F. An example is H2O.
Hydrogen bonds are typically quite strong.
Types of Intermolecular Forces within Pure Substances (cont) Hydrogen Bonds
Hydrogen bonds are a special type of dipole-dipole interaction.
Hydrogen bonds can occur when H is bonded to one of the highly electronegative atoms N, O, or F. An example is H2O.
Hydrogen bonds are typically quite strong.
Hydrogen Bonds in WaterHydrogen Bonds in Water
MixturesMixtures
Forming Solutions Like dissolves like
Ionic solutes often dissolve in polar solvents;e.g., NaCl dissolves in H2O.
Polar solutes generally dissolve in polar solvents; e.g., NH3 in H2O.
Nonpolar solutes generally do not dissolve well in polar solvents; e.g., oil in H2O.
Forming Solutions Like dissolves like
Ionic solutes often dissolve in polar solvents;e.g., NaCl dissolves in H2O.
Polar solutes generally dissolve in polar solvents; e.g., NH3 in H2O.
Nonpolar solutes generally do not dissolve well in polar solvents; e.g., oil in H2O.
NaCl Dissolving in H2ONaCl Dissolving in H2O
Emulsions Emulsifying agents are molecules that
contain a polar portion and a nonpolar region.
Soap is an example of an emulsifying agent that can form a suspension of a nonpolar material in a polar solvent (an “emulsion”).
Emulsions Emulsifying agents are molecules that
contain a polar portion and a nonpolar region.
Soap is an example of an emulsifying agent that can form a suspension of a nonpolar material in a polar solvent (an “emulsion”).
Emulsification with SoapEmulsification with Soap
Measuring Amounts in Solution Solubility
The maximum amount of a solute that dissolves in a solvent
Molarity The amount of a solute dissolved in a
solvent is its concentration. Concentration is often measured in
moles/liter, also called molarity (M).
Measuring Amounts in Solution Solubility
The maximum amount of a solute that dissolves in a solvent
Molarity The amount of a solute dissolved in a
solvent is its concentration. Concentration is often measured in
moles/liter, also called molarity (M).
Acid-Base Chemistry Definitions of Acids and Bases
Acids turn litmus paper red; bases turn litmus paper blue.
Acids produce H+ in solution; bases produce OH- in solution.
Acids are proton donors; bases are proton acceptors.
Acid-Base Chemistry Definitions of Acids and Bases
Acids turn litmus paper red; bases turn litmus paper blue.
Acids produce H+ in solution; bases produce OH- in solution.
Acids are proton donors; bases are proton acceptors.
Acid-Base Chemistry (cont) The pH Scale: a measure of acidity
Acid-Base Chemistry (cont) The pH Scale: a measure of acidity
Acid-Base Chemistry (cont) Acid-Base Indicators
Molecular sensors of H+.
Acid-Base Chemistry (cont) Acid-Base Indicators
Molecular sensors of H+.
H+
Acid-Base Chemistry (cont) Neutralization Reactions: equal molar
amounts of an acid and a base react to form a neutral solution.
Acid-Base Chemistry (cont) Neutralization Reactions: equal molar
amounts of an acid and a base react to form a neutral solution.
HCl + NaOH NaCl + H2O
Acid-Base Chemistry (cont) Buffers: contain a weak acid and its
conjugate base, which react with added H+ or OH- to prevent pH changes.
Acid-Base Chemistry (cont) Buffers: contain a weak acid and its
conjugate base, which react with added H+ or OH- to prevent pH changes.
HA H+ + A-
Adding acid: H+ reacts with A- to make more HA
Adding base: OH- reacts with HA to make more A- and H2O