| Term |
Definition |
Section of Book |
| abbreviated electron configuration |
An electron configuration that uses one of the noble gases to represent the core of electrons up to that element |
Organization of Electrons in Atoms |
| absolute zero |
The minimum possible temperature, labeled 0 K (zero kelvins) |
Other Units: Temperature and Density |
| acid |
An ionic compound of the H+ cation dissolved in water |
Acids |
| acid |
A compound that increases the amount of H+ ions in an aqueous solution |
Neutralization Reactions |
| acid dissociation constant (Ka) |
The equilibrium constant for the dissociation of a weak acid into ions |
Some Special Types of Equilibria |
| acid salt |
An ionic compound whose aqueous solution is slightly acidic |
Strong and Weak Acids and Bases and Their Salts |
| activated complex |
See transition state |
Reaction Mechanisms |
| activation energy (Ea) |
The minimum amount of kinetic energy molecules must possess for an effective collision to occur |
Factors that Affect the Rate of Reactions |
| active site |
Area of enzymatic action where substrate molecules react |
Catalysis |
| activity series |
A list of elements that will replace elements below them in single-replacement reactions |
Types of Chemical Reactions: Single- and Double-Displacement Reactions |
| actual yield |
The amount that is actually produced in a chemical reaction |
Yields |
| addition reaction |
A reaction where atoms are added across a double or triple bond |
Hydrocarbons |
| adhesion |
The tendency of a substance to interact with other substances because of intermolecular forces |
Properties of Liquids |
| adsorb |
Bind to the surface of another substance |
Catalysis |
| alcohol |
An organic compound that contains an OH functional group |
Alkyl halides and alcohols |
| aldehyde |
A compound that has a carbonyl functional group at the end of a chain of C atoms |
Other Oxygen-Containing Functional Groups |
| aliphatic hydrocarbons |
A hydrocarbon based on chains of C atoms |
Hydrocarbons |
| alkaline battery |
A type of dry cell that contains an alkaline (i.e., basic) moist paste, rather than an acidic paste |
Applications of Redox Reactions: Voltaic Cells |
| alkane |
An aliphatic hydrocarbon with only single covalent bonds |
Hydrocarbons |
| alkene |
An aliphatic hydrocarbon that contains a C–C double bond |
Hydrocarbons |
| alkyl halide |
An organic compound that contains a halogen atom |
Alkyl halides and alcohols |
| alkyne |
An aliphatic hydrocarbon that contains a C–C triple bond |
Hydrocarbons |
| alpha particle |
A type of radioactive emission equivalent to a helium nucleus |
Radioactivity |
| amide group |
A functional group that is the combination of the amine and carbonyl functional groups |
Other Functional Groups |
| amide bond |
The bond between the N atom and the C atom in an amide. |
Other Functional Groups |
| amine |
An organic derivative of ammonia |
Other Functional Groups |
| amorphous solid |
A solid with no long-term structure or repetition |
Solids |
| amphiprotic |
A substance that can act as a proton donor or a proton acceptor |
Brønsted-Lowry Acids and Bases |
| analyte |
The reagent of unknown concentration |
Acid-Base Titrations |
| angular momentum quantum number (ℓ) |
An index that affects the energy and the spatial distribution of an electron in an atom |
Quantum Numbers for Electrons |
| anion |
A species with an overall negative charge |
Ions and Ionic Compounds |
| anode |
The half cell that contains the oxidation reaction |
Applications of Redox Reactions: Voltaic Cells |
| antibonding molecular orbital |
A higher energy molecular orbital generated by destructive combination of atomic orbitals |
Molecular Orbitals |
| aromatic hydrocarbons |
Flat ring systems, which contain continuously overlapping p orbitals, such as benzene |
Hydrocarbons |
| Arrhenius acid |
A compound that increases the hydrogen ion concentration in aqueous solution |
Arrhenius Acids and Bases |
| Arrhenius base |
A compound that increases the hydroxide ion concentration in aqueous solution |
Arrhenius Acids and Bases |
| atmosphere (atm) |
A unit of pressure equal to the average atmospheric pressure at sea level; defined as exactly 760 mmHg |
Pressure |
| atom |
The smallest piece of an element that maintains the identity of that element |
Atomic Theory |
| atomic mass |
The sum of the number of protons and neutrons in a nucleus |
Atomic Theory |
| atomic mass |
The weighted average of the masses of the isotopes that compose an element |
Masses of Atoms and Molecules |
| atomic mass unit |
One-twelfth of the mass of a carbon-12 atom |
Masses of Atoms and Molecules |
| atomic number |
The number of protons in an atom |
Atomic Theory |
| atomic radius |
An indication of the size of an atom |
Periodic Trends |
| atomic symbol |
A one- or two-letter representation of the name of an element |
Atomic Theory |
| atomic theory |
The concept that atoms play a fundamental role in chemistry |
Atomic Theory |
| aufbau principle |
(German for “building up”): electrons fill the lowest energy orbitals first. |
Organization of Electrons in Atoms |
| autoionization constant of water (Kw) |
The product of the hydrogen ion and hydroxide ion concentrations |
Autoionization of Water |
| autoionization of water |
Water molecules act as acids (proton donors) and bases (proton acceptors) with each other to a tiny extent in all aqueous solutions |
Autoionization of Water |
| Avogadro’s law |
A gas law that relates number of particles to volume |
Other Gas Laws |
| balanced chemical equation |
A condition when the reactants and products of a chemical equation have the same number of atoms of all elements present |
The Chemical Equation |
| base |
A compound that increases the amount of OH− ions in an aqueous solution |
Neutralization Reactions |
| basic salt |
An ionic compound whose aqueous solution is slightly basic |
Strong and Weak Acids and Bases and Their Salts |
| becquerel (Bq) |
A unit of radioactivity equal to 1 decay per second |
Units of Radioactivity |
| beta particle |
A type of radioactive emission equivalent to an electron |
Radioactivity |
| boiling (or vaporization) |
The process of a liquid becoming a gas |
Phase Transitions: Melting, Boiling and Subliming |
| boiling point |
The characteristic temperature at which a liquid becomes a gas |
Phase Transitions: Melting, Boiling and Subliming |
| boiling point elevation |
The increase of a solution’s boiling point because of the presence of solute |
Colligative Properties of Solutions |
| boiling point elevation constant (Kb) |
The constant that relates the molality concentration of a solution and its boiling point change |
Colligative Properties of Solutions |
| bond energy |
The approximate amount of energy needed to break a covalent bond |
Other Aspects of Covalent Bonding |
| bond order |
A method of evaluating bond strength |
Molecular Orbitals |
| bonding electron pair |
A pair of electrons that makes a covalent bond |
Covalent Bonds |
| bonding molecular orbital |
The lower energy molecular orbital generated by constructive combination of atomic orbitals |
Molecular Orbitals |
| Boyle’s law |
A gas law that relates pressure and volume at constant temperature and amount |
Gas Laws |
| branched hydrocarbons |
A carbon compound that is not a straight chain, having substituents appended to the longest chain |
Branched Hydrocarbons |
| Brønsted-Lowry acid |
Any species that can donate a proton to another molecule |
Brønsted-Lowry Acids and Bases |
| Brønsted-Lowry base |
Any species that can accept a proton from another molecule |
Brønsted-Lowry Acids and Bases |
| buffer |
A solution that resists dramatic changes in pH |
Buffers |
| buffer capacity |
The amount of strong acid or base a buffer can counteract |
Buffers |
| burette or buret |
A precisely calibrated volumetric delivery tube |
Acid-Base Titrations |
| calorie |
A unit of energy measurement originally defined in terms of warming up a given quantity of water. 1 cal = 4.184 J |
Energy |
| calorimeter |
A container used to measure the heat of a chemical reaction |
Enthalpy and Chemical Reactions |
| calorimetry |
The process of measuring enthalpy changes for chemical reactions |
Enthalpy and Chemical Reactions |
| capillary action |
The behavior of a liquid in narrow surfaces due to differences in adhesion and cohesion |
Properties of Liquids |
| carbonyl group |
A functional group where an O atom and a C atom are joined with a double bond |
Other Oxygen-Containing Functional Groups |
| carboxyl group |
A functional group composed of a carbonyl group and an OH group |
Other Oxygen-Containing Functional Groups |
| carboxylate ion |
A negatively charged ion derived from a carboxylic acid |
Other Oxygen-Containing Functional Groups |
| carboxylic acid |
A molecule with a carboxyl group |
Other Oxygen-Containing Functional Groups |
| catalyst |
A substance that increases the speed of a reaction |
Shifting Equilibria: Le Chatelier’s Principle |
| catalyst |
A substance thaty accelerates a reaction by participating in it without being consumed |
Factors that Affect the Rate of Reactions |
| catalyst |
A substance that lowers the activation energy of a specific reaction by providing an alternate reaction pathway |
Catalysis |
| cathode |
The half cell that contains the reduction reaction |
Applications of Redox Reactions: Voltaic Cells |
| cation |
A species with an overall positive charge |
Ions and Ionic Compounds |
| central atom |
The atom in the center of a molecule |
Covalent Bonds |
| Charles’s law |
A gas law that relates volume and temperature at constant pressure and amount |
Gas Laws |
| chemical bond |
The connection between two atoms in a molecule |
Molecules an Chemical Nomenclature |
| chemical change |
The process of demonstrating a chemical property |
Some Basic Definitions |
| chemical equation |
A concise way of representing a chemical reaction |
The Chemical Equation |
| chemical equilibrium |
The point at which forward and reverse chemical reactions balance each other’s progress |
Chemical Equilibrium |
| chemical nomenclature |
A very specific system for naming compounds, in which unique substances get unique names |
Molecules an Chemical Nomenclature |
| chemical property |
A characteristic that describes how matter changes form in the presence of other matter |
Some Basic Definitions |
| chemistry |
The study of the interactions of matter with other matter and with energy |
Introduction |
| coefficient |
The part of a number in scientific notation that is multiplied by a power of 10 |
Expressing Numbers |
| coefficient |
A number in a chemical equation indicating more than one molecule of the substance |
The Chemical Equation |
| cohesion |
The tendency of a substance to interact with itself |
Properties of Liquids |
| colligative property |
A property of solutions related to the fraction that the solute particles occupy in the solution, not their identity |
Colligative Properties of Solutions |
| collision theory |
The theory that reactions occur when reactant molecules “effectively collide” |
Factors that Affect the Rate of Reactions |
| combined gas law |
A gas law that combines pressure, volume, and temperature |
Other Gas Laws |
| combustion reaction |
A chemical reaction in which a reactant combines with oxygen to produce oxides of all other elements as products |
Composition, Decomposition, and Combustion Reactions |
| complete ionic equation |
A chemical equation in which the dissolved ionic compounds are written as separated ions |
Ionic Equations: A Closer Look |
| composition reaction |
A chemical reaction in which a single substance is produced from multiple reactants |
Composition, Decomposition, and Combustion Reactions |
| compound |
A combination of more than one element |
Some Basic Definitions |
| compressibility factor |
A measure of the extent of deviation from ideal gas behaviour |
Real Gases |
| concentrated solution |
A solution with a lot of solute |
Some Definitions |
| concentration |
How much solute is dissolved in a given amount of solvent |
Some Definitions |
| concentration (verb) |
The removal of solvent, which increases the concentration of the solute in the solution |
Dilutions and Concentrations |
| condensation |
The process of a gas becoming a liquid |
Phase Transitions: Melting, Boiling and Subliming |
| condensed structure |
A listing of the atoms bonded to each C atom in a chain |
Hydrocarbons |
| conjugate acid-base pair |
Two species whose formulas differ by only a hydrogen ion |
Brønsted-Lowry Acids and Bases |
| continuous spectrum |
An image that contains all colors of light |
Quantum Numbers for Electrons |
| conversion factor |
A fraction that can be used to convert a quantity from one unit to another |
Converting Units |
| covalent bond |
A chemical bond formed by two atoms sharing electrons |
Covalent Bonds |
| covalent network solids |
A crystalline solid composed of atoms of one or more elements that are covalently bonded together in a seemingly never-ending fashion |
Solids |
| critical point |
The point at the highest temperature and pressure at which liquids and gases remain distinguishable |
Properties of Liquids |
| crystalline solid |
A solid with a regular, repeating three-dimensional structure |
Solids |
| curie |
A unit of radioactivity equal to 3.7×1010 decays/s |
Units of Radioactivity |
| d block |
The columns of the periodic table in which d subshells are being occupied |
Electronic Structure and the Periodic Table |
| Dalton’s law of partial pressures |
The total pressure of a gas mixture, Ptot, is equal to the sum of the partial pressures of the components, Pi |
Gas Mixtures |
| daughter isotope |
The product left over from the parent isotope in a nuclear equation |
Radioactivity |
| decomposition reaction |
A chemical reaction in which a single substance becomes more than one substance |
Composition, Decomposition, and Combustion Reactions |
| degrees |
The unit of temperature scales |
Other Units: Temperature and Density |
| density |
A physical property defined as a substance’s mass divided by its volume |
Other Units: Temperature and Density |
| deposition |
The process of a gas becoming a solid |
Phase Transitions: Melting, Boiling and Subliming |
| derived unit |
A unit that is a product or a quotient of a fundamental unit |
Expressing Units |
| diatomic molecule |
A molecule with only two atoms |
Molecules an Chemical Nomenclature |
| diffusion |
The movement of gas molecules through one or more additional types of gas via random molecular motion |
Molecular Effusion and Diffusion |
| dilute |
A solution with very little solute |
Some Definitions |
| dilution |
The addition of solvent, which decreases the concentration of the solute in the solution |
Dilutions and Concentrations |
| dilution equation |
The mathematical formula for calculating new concentrations or volumes when a solution is diluted or concentrated |
Dilutions and Concentrations |
| dipole-dipole interactions |
An intermolecular force caused by molecules with a permanent dipole |
Intermolecular Forces |
| dispersion force (or London dispersion force) |
An intermolecular force caused by the instantaneous position of an electron in a molecule |
Intermolecular Forces |
| dissociation |
The process of an ionic compound separating into ions when it dissolves |
Ionic Equations: A Closer Look |
| double bond |
A covalent bond composed of two pairs of bonding electrons |
Covalent Bonds |
| double-replacement reaction |
A chemical reaction in which parts of two ionic compounds are exchanged |
Types of Chemical Reactions: Single- and Double-Displacement Reactions |
| dry cell |
A modern battery that does not contain large amounts of aqueous solution |
Applications of Redox Reactions: Voltaic Cells |
| dynamic equilibrium |
When a process still occurs but the opposite process also occurs at the same rate so that there is no net change in the system. |
Properties of Liquids |
| effective nuclear charge (Zeff) |
The net nuclear charge feld by valence electrons |
Periodic Trends |
| effusion |
The movement of gas molecules from one container to another via a tiny hole |
Molecular Effusion and Diffusion |
| electrodes |
The cathode or anode of a voltaic cell |
Applications of Redox Reactions: Voltaic Cells |
| electrolysis |
The process of making a nonspontaneous redox reaction occur by forcing electricity into a cell |
Electrolysis |
| electrolytic cell |
A cell into which electricity is forced to make a nonspontaneous reaction occur |
Electrolysis |
| electromagnetic spectrum |
The full span of the possible wavelengths, frequencies, and energies of light |
Light |
| electron |
A tiny subatomic particle with a negative charge |
Atomic Theory |
| electron affinity (EA) |
The energy change when a gas-phase atom accepts an electron |
Periodic Trends |
| electron configuration |
A listing of the shell and subshells labels |
Organization of Electrons in Atoms |
| electron deficient molecules |
A molecule with less than eight electrons in the valence shell of an atom |
Violations of the Octet Rule |
| electron group geometry |
how electron groups (bonds and nonbonding electron pairs) are arranged |
Molecular Shapes and Polarity |
| electron groups |
A covalent bond of any type or a lone electron pair |
Molecular Shapes and Polarity |
| electron shell |
A term used to describe electrons with the same principal quantum number |
Quantum Numbers for Electrons |
| electronegativity |
A scale for judging how much atoms of any element attract electrons |
Other Aspects of Covalent Bonding |
| electroplating |
The deposition of a thin layer of metal on an object for protective or decorative purposes |
Electrolysis |
| element |
A substance that cannot be broken down into simpler chemical substances by ordinary chemical means |
Some Basic Definitions |
| elementary step |
Each event that occurs in a chemical reaction as a result of an effective collision |
Reaction Mechanisms |
| elimination reaction |
The removal of a functional group (either X or OH) and a H atom from an adjacent carbon |
Alkyl halides and alcohols |
| endothermic |
A chemical reaction that has a positive change in enthalpy |
Enthalpy and Chemical Reactions |
| energy |
The ability to do work. is the ability to do work |
Energy |
| enthalpy change |
The heat of a process at constant pressure; denoted ΔH |
Enthalpy and Chemical Reactions |
| enthalpy of formation |
The enthalpy change for a formation reaction; denoted ΔHf. and is given the symbol ΔHf |
Formation Reactions |
| enthalpy of fusion |
The amount of energy needed to change from a solid to a liquid or from a liquid to a solid |
Phase Transitions: Melting, Boiling and Subliming |
| enthalpy of sublimation |
The amount of energy needed to change from a solid to a gas or from a gas to a solid |
Phase Transitions: Melting, Boiling and Subliming |
| enthalpy of vaporization |
The amount of energy needed to change from a liquid to a gas or from a gas to a liquid |
Phase Transitions: Melting, Boiling and Subliming |
| entropy |
The level of randomness (or disorder) of a system, or a measure of the energy dispersal of the molecules in the system |
Entropy and the Second Law of Thermodynamics |
| enzyme |
Protein molecules which serve to catalyze biochemical reactions |
Catalysis |
| enzyme-substrate complex |
The binding of substrate to the enzymatic active site |
Catalysis |
| equilibrium constant (Keq) |
A numerical value that relates to the ratio of products and reactants at equilibrium |
The Equilibrium Constant |
| equivalence point |
The point of the reaction when all the analyte has been reacted with the titrant |
Acid-Base Titrations |
| ester group |
A functional group made by combining a carboxylic acid with an alcohol |
Other Oxygen-Containing Functional Groups |
| ether group |
A functional group that has an O atom attached to two organic groups |
Other Oxygen-Containing Functional Groups |
| evaporation |
The formation of a gas phase from a liquid at temperatures below the boiling point |
Properties of Liquids |
| exact number |
A number from a defined relationship that technically has an infinite number of significant figures |
Converting Units |
| exothermic |
A chemical reaction that has a negative change in enthalpy |
Enthalpy and Chemical Reactions |
| expanded valence shell molecules |
A molecule with more than eight electrons in the valence shell of an atom |
Violations of the Octet Rule |
| experiment |
A test of the natural universe to see if a guess (hypothesis) is correct |
Chemistry as a Science |
| exponent |
The raised number to the right of a 10 indicating the number of factors of 10 in the original number |
Expressing Numbers |
| f block |
The columns of the periodic table in which f subshells are being occupied |
Electronic Structure and the Periodic Table |
| fission |
The breaking apart of an atomic nucleus into smaller nuclei |
Radioactivity |
| formation reaction |
A chemical reaction that forms one mole of a substance from its constituent elements in their standard states |
Formation Reactions |
| freezing point depression |
The decrease of a solution’s freezing point because of the presence of solute |
Colligative Properties of Solutions |
| freezing point depression constant (Kf) |
The constant that relates the molality concentration of a solution and its freezing point change |
Colligative Properties of Solutions |
| frequency |
The number of cycles of light that pass a given point in one second |
Light |
| frequency factor (A) |
A factor that takes into account the frequency of reactions and the likelihood of correct molecular orientation |
Activation Energy and the Arrhenius Equation |
| frontier molecular orbitals |
A term which refers to the HOMO and LUMO, the most likely orbitals to be involved in chemical reactions or processes |
Molecular Orbitals |
| functional group |
A collection of atoms or bonds with certain characteristic reactions |
Alkyl halides and alcohols |
| fundamental units |
One of the seven basic units of SI used in science |
Expressing Units |
| gamma ray |
A type of radioactive emission that is a very energetic form of electromagnetic radiation |
Radioactivity |
| gas law |
A simple mathematical formula that allows one to model, or predict, the behavior of a gas |
Gas Laws |
| Gay-Lussac’s law |
A gas law that relates pressure with absolute temperature |
Other Gas Laws |
| Geiger counter |
An electrical device that detects radioactivity |
Units of Radioactivity |
| Gibbs free energy (G) |
A measure of spontaneity which incorporates both enthalpy and entropy |
Gibbs Free Energy |
| Graham’s law of effusion |
A law which relates the rate of effusion of a gas to the inverse of the square root of its molar mass |
Molecular Effusion and Diffusion |
| gray (Gy) |
A unit of radioactive exposure qual to 100 rad |
Units of Radioactivity |
| half cell |
A part of a voltaic cell that contains one half reaction |
Applications of Redox Reactions: Voltaic Cells |
| half reaction |
The individual oxidation or reduction reaction of a redox reaction |
Balancing Redox Reactions |
| half reaction method |
The method of balancing redox reactions by writing and balancing the individual half reactions |
Balancing Redox Reactions |
| half-life |
The amount of time it takes for one-half of a radioactive isotope to decay |
Half-Life |
| half-life |
The amount of time required for the concentration of a reactant to drop to one half of its initial concentration |
Concentration-Time Relationships: Integrated Rate Laws |
| heat |
The transfer of energy from one body to another due to a difference in temperature |
Work and Heat |
| heating curve |
A plot of the temperature versus the amount of heat added |
Phase Transitions: Melting, Boiling and Subliming |
| Hess’s law |
When chemical equations are combined algebraically, their enthalpies can be combined in exactly the same way |
Hess’s Law |
| heterogeneous catalyst |
A catalyst that is in a different phase from one or more of the reactants |
Catalysis |
| heterogeneous equilibrium |
An equilibrium in which more than one phase of reactants or products is present |
The Equilibrium Constant |
| heterogeneous mixture |
A non-uniform combination of more than one substance |
Some Basic Definitions |
| HOMO |
The highest occupied molecular orbital |
Molecular Orbitals |
| homogeneous catalyst |
A catalyst that is present in the same phase as the reactant molecules |
Catalysis |
| homogeneous mixture |
A uniform mixture of more than one substance that behaves as a single substance |
Some Basic Definitions |
| Hund’s rule |
One electron is placed in each degenerate orbital before pairing electrons in the same orbital |
Organization of Electrons in Atoms |
| hybridization |
A mathematical mixing of atomic orbitals |
Valence Bond Theory and Hybrid Orbitals |
| hydrocarbons |
An organic compound composed of carbon and hydrogen |
Hydrocarbons |
| hydrogen bonding |
The very strong interaction between molecules due to H atoms being bonded to N, O, or F atoms |
Intermolecular Forces |
| hydrogenation reaction |
The reaction of hydrogen across a C–C double or triple bond, usually in the presence of a catalyst |
Hydrocarbons |
| hydronium ion |
The actual chemical species that represents a hydrogen ion in aqueous solution |
Arrhenius Acids and Bases |
| hypothesis |
An educated guess about how the natural universe works |
Chemistry as a Science |
| hyrolysis |
A reaction with water |
Brønsted-Lowry Acids and Bases |
| ICE chart |
A table used to calculate equilibria values featuring rows of initial, change and equlibria concentration |
Calculating Equilibrium Constant Values |
| ideal gas |
A gas that conforms exactly to the tenets of the kinetic molecular theory |
Real Gases |
| ideal gas law |
A gas law that relates all four independent physical properties of a gas under any conditions |
The Ideal Gas Law and Some Applications |
| indicator |
A substance whose color change indicates the equivalence point of a titration |
Acid-Base Titrations |
| initial rate |
The instantaneous rate at the start of a reaction |
Reaction Rates |
| initial rates method |
A method to determine the rate law from the instantaneous reaction rate upon mixing the reactants |
Rate Laws |
| instantaneous reaction rate |
The rate of reaction at one instant in time |
Reaction Rates |
| intermediate |
A chemical species does not appear in the overall balanced equation and is generated in one elementary step but used up in a subsequent step |
Reaction Mechanisms |
| ion |
A species with an overall electric charge |
Ions and Ionic Compounds |
| ionic compound |
A compound formed from positive and negative ions |
Ions and Ionic Compounds |
| ionic formula |
The chemical formula for an ionic compound |
Ions and Ionic Compounds |
| ionic solid |
A crystalline solid composed of ions |
Solids |
| ionization energy (IE) |
The amount of energy required to remove an elec tron from an atom in the gas phase |
Periodic Trends |
| isolated system |
A system that does not allow a transfer of energy or matter into or out of the system |
Energy |
| isomer |
A molecule with the same molecular formula as another molecule but a different structure |
Hydrocarbons |
| isothermal |
A process that does not change the temperature |
Phase Transitions: Melting, Boiling and Subliming |
| isotopes |
Atoms of the same element that have different numbers of neutrons |
Atomic Theory |
| joule |
The SI unit of energy |
Energy |
| Kelvin scale |
The fundamental unit of temperature in SI |
Other Units: Temperature and Density |
| ketone |
A compound where the carbonyl carbon is attached to two carbon chains |
Other Oxygen-Containing Functional Groups |
| kinetic energy |
The energy due to motion |
Kinetic-Molecular Theory of Gases |
| kinetic-molecular theory of gases |
A model which helps us understand gases at the molecular level and their physical properties |
Kinetic-Molecular Theory of Gases |
| kinetics |
The study of reaction rate and the factors that can influence reaction rate |
Introduction to Kinetics |
| law of conservation of energy |
The total energy of an isolated system does not increase or decrease |
Energy |
| law of mass action |
The relationship of the amounts of reactants and products at equilibrium |
The Equilibrium Constant |
| Le Chatelier’s principle |
If an equilibrium is stressed, then the reaction shifts to reduce the stress |
Shifting Equilibria: Le Chatelier’s Principle |
| Lewis diagram |
A representation of the valence electrons of an atom that uses dots around the symbol of the element |
Lewis Electron Dot Diagrams |
| limiting reagent |
The reactant that runs out first for a given chemical reaction |
Limiting Reagents |
| line spectrum |
An image that contains only certain colors of light |
Quantum Numbers for Electrons |
| locant |
The numerical position of a substituent |
Branched Hydrocarbons |
| lock and key model |
A simple model used to describe enzyme activity, where substrates must fit into appropriately shaped active sites |
Catalysis |
| lone electron pairs |
A pair of electrons that does not make a covalent bond |
Covalent Bonds |
| LUMO |
The lowest unoccupied molecular orbital |
Molecular Orbitals |
| magnetic quantum number (ml) |
The index that determines the orientation of the electron’s spatial distribution |
Quantum Numbers for Electrons |
| mass-mass calculation |
A calculation in which you start with a given mass of a substance and calculate the mass of another substance involved in the chemical equation |
Mole-Mass and Mass-Mass Calculations |
| matter |
Anything that has mass and takes up space. is anything that has mass and takes up space |
Some Basic Definitions |
| mean free path |
The average distance traveled by a molecule between collisions |
Molecular Effusion and Diffusion |
| melting |
The process of a solid becoming a liquid |
Phase Transitions: Melting, Boiling and Subliming |
| melting point |
The characteristic temperature at which a solid becomes a liquid |
Phase Transitions: Melting, Boiling and Subliming |
| meniscus |
The curved surface a liquid makes as it approaches a solid barrier |
Properties of Liquids |
| metal |
An element that conducts electricity and heat well and is shiny, silvery, solid, ductile, and malleable |
Some Basic Definitions |
| metallic solid |
A solid with the characteristic properties of a metal |
Solids |
| microstate (W) |
A term used to describe different possible arrangements of molecular position and kinetic energy, at a particular thermodynamic state |
Entropy and the Second Law of Thermodynamics |
| millimeters of mercury (mmHg) |
The amount of pressure exerted by a column of mercury exactly 1 mm high |
Pressure |
| mixture |
A physical combination of more than one substance |
Some Basic Definitions |
| molality (m) |
The number of moles of solute per kilogram of solvent |
Quantitative Units of Concentration |
| molar mass |
The mass of 1 mol of a substance in grams |
The Mole |
| molar volume |
The volume of exactly 1 mol of a gas; equal to 22.4 L at STP |
The Ideal Gas Law and Some Applications |
| molarity (M) |
The number of moles of solute divided by the number of liters of solution |
Quantitative Units of Concentration |
| mole |
The number of things equal to the number of atoms in exactly 12 g of carbon-12; equals 6.022×1023 things |
The Mole |
| mole fraction |
The ratio of the number of moles of a component in a mixture divided by the total number of moles in the sample |
Gas Mixtures |
| mole fraction |
The ratio of the number of moles of a component to the total number of moles in a system |
Colligative Properties of Solutions |
| molecular formula |
A formal listing of what and how many atoms are in a molecule |
Molecules an Chemical Nomenclature |
| molecular geometry |
how the atoms in a molecule are arranged |
Molecular Shapes and Polarity |
| molecular mass |
The sum of the masses of the atoms in a molecule |
Masses of Atoms and Molecules |
| molecular orbital theory (MO theory) |
A more sophisticated model of chemical bonding where new molecular orbitals are generated using a mathematical process called Linear Combination of Atomic Orbitals (LCAO) |
Molecular Orbitals |
| molecular polarity |
The vector sum of the individual bond dipoles |
Molecular Shapes and Polarity |
| molecular solid |
A crystalline solid whose components are covalently bonded molecules |
Solids |
| molecularity |
The total number of molecules that participate in the effective collision of the elementary step |
Reaction Mechanisms |
| molecule |
The smallest part of a substance that has the physical and chemical properties of that substance |
Molecules an Chemical Nomenclature |
| mole-mass calculation |
A calculation in which you start with a given number of moles of a substance and calculate the mass of another substance involved in the chemical equation, or vice versa |
Mole-Mass and Mass-Mass Calculations |
| mole-mole calculation |
A stoichiometry calculation when one starts with moles of one substance and convert to moles of another substance using the balanced chemical equation |
The Mole in Chemical Reactions |
| monomer |
The repeated unit of a polymer |
Polymers |
| net ionic equation |
A chemical equation with the spectator ions removed |
Ionic Equations: A Closer Look |
| neutral salt |
An ionic compound that does not affect the acidity of its aqueous solution |
Strong and Weak Acids and Bases and Their Salts |
| neutralization reaction |
The reaction of an acid with a base to produce water and a salt |
Neutralization Reactions |
| neutralization reaction |
The reaction of an acid and a base to produce water and a salt |
Arrhenius Acids and Bases |
| neutron |
A subatomic particle with no charge |
Atomic Theory |
| node (nodal plane) |
An area of zero electron density |
Molecular Orbitals |
| nomenclature |
The rules of naming in organic chemistry |
Branched Hydrocarbons |
| nonmetal |
An element that exists in various colors and phases, is brittle, and does not conduct electricity or heat well |
Some Basic Definitions |
| nonpolar covalent bond |
The equal sharing of electrons in a covalent bond |
Other Aspects of Covalent Bonding |
| normal boiling point |
The characteristic temperature at which a liquid becomes a gas when the surrounding pressure is exactly 1 atm |
Phase Transitions: Melting, Boiling and Subliming |
| nuclear energy |
The controlled harvesting of energy from fission reactions |
Nuclear Energy |
| nuclear equation |
A chemical equation that emphasizes changes in atomic nuclei |
Radioactivity |
| nuclear model |
The model of an atom that has the protons and neutrons in a central nucleus with the electrons in orbit about the nucleus |
Atomic Theory |
| nucleus |
The center of an atom that contains protons and neutrons |
Atomic Theory |
| odd-electron molecules |
A molecule with an odd number of electrons in the valence shell of an atom |
Violations of the Octet Rule |
| orbital |
The specific set of principal, angular momentum, and magnetic quantum numbers for an electron |
Quantum Numbers for Electrons |
| osmosis |
The tendency of solvent molecules to pass through a semipermeable membrane due to concentration differences |
Colligative Properties of Solutions |
| osmotic pressure |
The tendency of a solution to pass solvent through a semipermeable membrane due to concentration differences |
Colligative Properties of Solutions |
| oxidation |
The loss of one or more electrons by an atom; an increase in oxidation number |
Oxidation-Reduction Reactions |
| oxidation |
The loss of one or more electrons by an atom; an increase in oxidation number |
Oxidation-Reduction Reactions |
| oxidation number |
A number assigned to an atom that helps keep track of the number of electrons on the atom |
Oxidation-Reduction Reactions |
| oxidation number |
A number assigned to an atom that helps keep track of the number of electrons on the atom |
Oxidation-Reduction Reactions |
| oxidation-reduction (redox) reactions |
A chemical reaction that involves the transfer of electrons |
Oxidation-Reduction Reactions |
| p block |
The columns of the periodic table in which p subshells are being occupied |
Electronic Structure and the Periodic Table |
| parent isotope |
The reactant in a nuclear equation |
Radioactivity |
| parts per billion (ppb) |
Ratio of mass of solute to total mass of sample times 1,000,000,000 |
Quantitative Units of Concentration |
| parts per million (ppm) |
Ratio of mass of solute to total mass of sample times 1,000,000 |
Quantitative Units of Concentration |
| parts per thousand (ppth) |
Ratio of mass of solute to total mass of sample times 1,000 |
Quantitative Units of Concentration |
| Pauli exclusion principle |
No two electrons in an atom can have the same set of four quantum numbers |
Organization of Electrons in Atoms |
| percent yield |
Actual yield divided by theoretical yield times 100% to give a percentage between 0% and 100% |
Yields |
| percentage composition by mass (or mass percentage, % m/m) |
Ratio of mass of solute to the total mass of a sample times 100 |
Quantitative Units of Concentration |
| periodic table |
A chart of all the elements |
Atomic Theory |
| periodic trends |
The variation of properties versus position on the periodic table |
Periodic Trends |
| pH |
The negative logarithm of the hydrogen ion concentration |
The pH Scale |
| pH scale |
The range of values from 0 to 14 that describes the acidity or basicity of a solution |
The pH Scale |
| phase |
An important physical property that defines whether matter is a solid, liquid, gas or supercritical fluid |
Some Basic Definitions |
| phase diagram |
A graphical representation of the equilibrium relationships that exist between the phases of a substance under specified pressures and temperatures |
Properties of Liquids |
| photon |
The name of a discrete unit of light acting as a particle |
Light |
| physical change |
A change that occurs when a sample of matter changes one or more of its physical properties |
Some Basic Definitions |
| physical property |
A characteristic that describes matter as it exists |
Some Basic Definitions |
| pi bond (π bond) |
The sideways overlap of p orbitals, placing electron density on opposite sides of the inter-nuclear axis – a double or triple bond |
Valence Bond Theory and Hybrid Orbitals |
| Planck’s constant |
The proportionality constant between the frequency and the energy of light: 6.626 × 10−34 J·s |
Light |
| pOH |
The negative logarithm of the hydroxide ion concentration |
The pH Scale |
| polar covalent bond |
A covalent bond between different atoms that attract the shared electrons by different amounts and cause an imbalance of electron distribution |
Other Aspects of Covalent Bonding |
| polarity |
A measure of the unequal sharing of electrons which has resulted in a dipole moment |
Other Aspects of Covalent Bonding |
| polyatomic ions |
An ion that contains more than one atom |
Ions and Ionic Compounds |
| polymer |
A long molecule made of many repeating units |
Polymers |
| polymerization |
The process of making a polymer |
Polymers |
| polyprotic acid |
An acid capable of donating more than one H+ ion |
Some Special Types of Equilibria |
| precipitate |
A solid that falls out of solution in a precipitation reaction |
Types of Chemical Reactions: Single- and Double-Displacement Reactions |
| precipitation reaction |
A chemical reaction in which two ionic compounds are dissolved in water and form a new ionic compound that does not dissolve |
Types of Chemical Reactions: Single- and Double-Displacement Reactions |
| prefix |
A prefix used with a unit that refers to a multiple or fraction of a fundamental unit to make a more conveniently sized unit for a specific quantity |
Expressing Units |
| pressure |
Force per unit area |
Pressure |
| primary battery |
A battery that cannot be recharged |
Applications of Redox Reactions: Voltaic Cells |
| principal quantum number (n) |
The index that largely determines the energy of an electron in an atom |
Quantum Numbers for Electrons |
| product |
A final substance in a chemical equation |
The Chemical Equation |
| proton |
A subatomic particle with a positive charge |
Atomic Theory |
| qualitative |
A description of the quality of an object |
Chemistry as a Science |
| quantitative |
A description of a specific amount of something |
Chemistry as a Science |
| quantization |
When a quantity is restricted to having only certain values |
Quantum Numbers for Electrons |
| quantum mechanics |
The theory of electrons that treats them as a wave |
Quantum Numbers for Electrons |
| quantum number |
An index that corresponds to a property of an electron, like its energy |
Quantum Numbers for Electrons |
| rad |
A unit of radioactive exposure equal to 0.01 J/g of tissue |
Units of Radioactivity |
| radioactive decay |
The spontaneous change of a nucleus from one element to another |
Radioactivity |
| radioactivity |
Emanations of particles and radiation from atomic nuclei |
Radioactivity |
| Raoult’s law |
The mathematical formula for calculating the vapor pressure of a solution |
Colligative Properties of Solutions |
| rate constant (k) |
A proportionality constant specific to each reaction at a particular temperature |
Rate Laws |
| rate-determining step |
The slowest step in a multistep mechanism |
Reaction Mechanisms |
| rate law |
A mathematical relationship between the reaction rate and the reactant concentrations |
Rate Laws |
| reactant |
An initial substance in a chemical equation |
The Chemical Equation |
| reaction mechanism |
The bond making and bond breaking steps which occur at the molecular level during a chemical reaction |
Reaction Mechanisms |
| reaction order |
The sum of the concentration term exponents in a rate law equation |
Rate Laws |
| reaction rate |
The speed of a chemical reaction |
Introduction to Kinetics |
| real gases |
A gas that deviates from ideal behaviour |
Real Gases |
| redox reaction |
A chemical reaction that involves the transfer of electrons |
Oxidation-Reduction Reactions |
| reduction |
The gain of one or more electrons by an atom; a decrease in oxidation number |
Oxidation-Reduction Reactions |
| reduction |
The gain of one or more electrons by an atom; a decrease in oxidation number |
Oxidation-Reduction Reactions |
| rem |
A unit of radioactive exposure that includes a factor to account for the type of radioactivity |
Units of Radioactivity |
| ribozyme |
Ribonucleic acid (RNA) molecules capable of catalyzing certain chemical reactions |
Catalysis |
| root-mean-square (rms) speed (urms) |
The speed of molecules having exactly the same kinetic energy as the average kinetic energy of the sample |
Kinetic-Molecular Theory of Gases |
| s block |
The columns of the periodic table in which s subshells are being occupied |
Electronic Structure and the Periodic Table |
| salt |
Any ionic compound that is formed from a reaction between an acid and a base |
Neutralization Reactions |
| salt |
Any ionic compound that is formed from a reaction between an acid and a base |
Arrhenius Acids and Bases |
| salt bridge |
A part of a voltaic cell that contains a solution of some ionic compound whose ions migrate to either side of the voltaic cell to maintain the charge balance |
Applications of Redox Reactions: Voltaic Cells |
| saturated hydrocarbons |
A carbon compound with the maximum possible number of H atoms in its formula |
Hydrocarbons |
| saturated solution |
A solution with the maximum amount of solute dissolved in it |
Some Definitions |
| science |
The process of knowing about the natural universe through observation and experiment |
Chemistry as a Science |
| scientific law |
A specific statement that is thought to be never violated by the entire natural universe |
Chemistry as a Science |
| scientific notation |
An expression of a number using powers of 10 |
Expressing Numbers |
| screening |
The repelling valence electrons by core electrons |
Periodic Trends |
| second law of thermodynamics |
A spontaneous process will increase the entropy of the universe |
Entropy and the Second Law of Thermodynamics |
| secondary battery |
A battery that can be recharged |
Applications of Redox Reactions: Voltaic Cells |
| semimetal |
An element that has properties of both metals and nonmetals |
Some Basic Definitions |
| semipermeable membrane |
A thin membrane that will pass certain small molecules but not others |
Colligative Properties of Solutions |
| SI unit |
International System of Units used by all scientists, literally translated from “le Système International d’unités.” |
Expressing Units |
| Sievert (Sv) |
Sievert (Sv) is a related unit and is defined as 100 rem |
Units of Radioactivity |
| sigma bond (σ bond) |
Orbital overlap to form a bond which has cylindrical symmetry – a single bond |
Valence Bond Theory and Hybrid Orbitals |
| significant figures |
The limit of the number of places a measurement can be properly expressed with |
Significant Figures |
| silicones |
A polymer based on a silicon and oxygen backbone |
Polymers |
| single bond |
A covalent bond composed of one pair of electrons |
Covalent Bonds |
| single-replacement reaction |
A chemical reaction in which one element is substituted for another element in a compound |
Types of Chemical Reactions: Single- and Double-Displacement Reactions |
| solidification |
The process of a liquid becoming a solid |
Phase Transitions: Melting, Boiling and Subliming |
| solubility |
The maximum amount of a solute that can be dissolved in a given amount of a solvent |
Some Definitions |
| solubility rules |
General statements that predict which ionic compounds dissolve and which do not |
Types of Chemical Reactions: Single- and Double-Displacement Reactions |
| solute |
The minor component of a solution |
Some Definitions |
| solution |
See homogeneous mixture |
Some Basic Definitions |
| solvent |
The major component of a solution |
Some Definitions |
| specific heat capacity |
The proportionality constant between heat, mass, and temperature change; also called specific heat |
Work and Heat |
| spectator ion |
An ion that does nothing in the overall course of a chemical reaction |
Ionic Equations: A Closer Look |
| spin quantum number (ms) |
The index that indicates one of two spin states for an electron |
Quantum Numbers for Electrons |
| spontaneous process |
A process that occurs without the influence of external forces or a change that moves a system towards equilibrium |
Spontaneous Change |
| standard molar entropy (So) |
The entropy of 1 mole of a substance in its standard state, at 1 atm of pressure |
Measuring Entropy and Entropy Changes |
| standard notation |
A straightforward expression of a number |
Expressing Numbers |
| standard temperature and pressure (STP) |
A set of benchmark conditions used to compare other properties of gases; 100 kPa for pressure and 273 K for temperature |
The Ideal Gas Law and Some Applications |
| stoichiometry |
The relating of one chemical substance to another using a balanced chemical reaction |
Stoichiometry |
| strong acid |
Any acid that is 100% dissociated into ions in aqueous solution |
Strong and Weak Acids and Bases and Their Salts |
| strong base |
Any base that is 100% dissociated into ions in aqueous solution |
Strong and Weak Acids and Bases and Their Salts |
| sublimation |
The process of a solid becoming a gas |
Phase Transitions: Melting, Boiling and Subliming |
| subshell |
A term used to describe electrons in a shell that have the same angular momentum quantum number |
Quantum Numbers for Electrons |
| substance |
Matter that has the same physical and chemical properties throughout. |
Some Basic Definitions |
| substituent |
A branch off a main chain in a hydrocarbon |
Branched Hydrocarbons |
| substrate |
The reactants which are specific for a biological catalyst |
Catalysis |
| supercritical fluid |
A phase beyond the critical point, where liquid and gas phases are no longer distinct |
Properties of Liquids |
| supersaturated solution |
A unstable solution with more than the normal maximum amount of solute in it |
Some Definitions |
| surface tension |
An effect caused by an imbalance of forces on the atoms at the surface of a liquid |
Properties of Liquids |
| surrounding atoms |
An atom that makes covalent bonds to the central atom(s) |
Covalent Bonds |
| system |
The part of the universe under study |
Energy |
| temperature |
A measure of the average amount of kinetic energy a system contains |
Other Units: Temperature and Density |
| theoretical yield |
An amount that is theoretically produced as calculated using the balanced chemical reaction |
Yields |
| theory |
A general statement that explains a large number of observations |
Chemistry as a Science |
| thermochemical equation |
A chemical equation that includes an enthalpy change |
Enthalpy and Chemical Reactions |
| thiol |
The sulfur analog of an alcohol |
Other Functional Groups |
| third law of thermodynamics |
At absolute zero the entropy of a pure, perfect crystal is zero |
Measuring Entropy and Entropy Changes |
| titrant |
The reagent of known concentration |
Acid-Base Titrations |
| titration |
A chemical reaction performed quantitatively to determine the exact amount of a reagent |
Acid-Base Titrations |
| torr |
Another name for a millimeter of mercury |
Pressure |
| tracer |
A substance that can be used to follow the pathway of that substance through a structure |
Uses of Radioactive Isotopes |
| transition state |
The highest energy transitional point in the elementary step |
Reaction Mechanisms |
| triple bond |
A covalent bond composed of three pairs of bonding electrons |
Covalent Bonds |
| unsaturated hydrocarbons |
A carbon compound with less than the maximum possible number of H atoms in its formula |
Hydrocarbons |
| unsaturated solution |
A solution with less than the maximum amount of solute dissolved in it |
Some Definitions |
| valence electrons |
The electrons in the highest-numbered shell, plus any electrons in the last unfilled subshell. The electrons most likely involved in chemical reactions |
Electronic Structure and the Periodic Table |
| valence shell |
The highest-numbered shell in an atom that contains electrons |
Electronic Structure and the Periodic Table |
| valence shell electron pair repulsion theory (VSEPR) |
The general concept that estimates the shape of a simple molecule: electron pairs repel each other to get as far away from each other as possible |
Molecular Shapes and Polarity |
| van der Waal’s equation |
An equation which compensates for deviations from ideal gas behaviour, correcting for intermolecular forces and the volume of gas molecules |
Real Gases |
| van’t Hoff factor (i) |
The number of particles each solute formula unit breaks apart into when it dissolves |
Colligative Properties of Ionic Solutes |
| vapor |
Material in the gas phase due to evaporation |
Properties of Liquids |
| vapor pressure |
The partial pressure exerted by evaporation of a liquid |
Gas Mixtures |
| vapor pressure depression |
The decrease of a solution’s vapor pressure because of the presence of a solute |
Colligative Properties of Solutions |
| vector quantity |
A quantity which has both a magnitude and direction |
Molecular Shapes and Polarity |
| voltaic (galvanic) cell |
An apparatus that allows for useful electrical work to be extracted from a redox reaction. |
Applications of Redox Reactions: Voltaic Cells |
| wavelength |
The distance between corresponding points in two adjacent light cycles |
Light |
| weak acid |
Any acid that is less than 100% dissociated into ions in aqueous solution |
Strong and Weak Acids and Bases and Their Salts |
| weak base |
Any base that is less than 100% dissociated into ions in aqueous solution |
Strong and Weak Acids and Bases and Their Salts |
