Term | Definition |
Mole Ratio | The ratio of moles of one substance to moles of another substance in a balanced chemical equation. |
Stoichiometry | The process of using a balanced chemical equation to determine the relative masses of reactants and products involved in a reaction. |
Limiting Reactant | The reactant that is completely used up when a reaction is run to completion. |
Theoretical Yield | The maximum amount of a given product that can be formed when the limiting reactant is completely consumed. |
Percent Yield | The actual yield of a product as the percentage of the theoretical yield. |
Energy | The ability to do work or to produce heat. |
Potential Energy | Energy due to position or composition. |
Kinetic Energy | Energy due to the motion of the object. |
Law of Conservation of Energy | Energy cannot be created or destroyed, but it can be converted from one form to another. |
Work | Force acting over a distance. |
State Function | A property of a system that does not depend on the pathway. |
Temperature | Measure of the random motions (average kinetic energy)of the components of a substance. |
Heat | Flow of energy due to a temperature difference. |
Exothermic | Refers to a process in which energy (as heat) flows out of the system into the surroundings. |
Endothermic | Refers to a process in which energy (as heat) flows from the surroundings into the system. |
Thermodynamics | The study of energy. |
First Law of Thermodynamics | The energy of the universe is constant. |
Internal Energy | Sum of the kinetic and potential energies of all particles in the system. |
Calorie | The amount of energy needed to raise the temperature of one gram of water by one Celsius degree. |
Specific Heat Capacity | The amount of energy needed to raise the temperature of one gram of a substance by one Celsius degree. |
Enthalpy | At constant pressure, a change in enthalpy is equal to the energy flow as heat. |
Calorimeter | A device used to determine the heat associated with a chemical or physical change. |
Hess's Law | The change in enthalpy in going from a given set of reactants to a given set of products does not depend on the number of steps in the reaction. |
Fossil Fuel | Fuel that consists of carbon-based molecules derived from the decomposition of once living organisms. |
Petroleum | A think, dark liquid composed mostly of hydrocarbon compounds. |
Natural Gas | A gaseous fossil fuel, mostly consisting methane and usually associated with petroleum deposits. |
Coal | A solid fossil fuel mostly consisting of carbon. |
Greenhouse Effect | The process by which an atmosphere warms a planet. |
Electromagnetic Radiation | Radiant energy that exhibits wavelike behavior and travels through space at the speed of light in a vacuum. |
Wavelength | The distance between two consecutive peaks or troughs in a wave. |
Frequency | The number of waves per second that pass a given point in space. |
Photon | A particle of electromagnetic radiation. |
Orbital | The three-dimensional region in which there is a high probability of finding an electron in an atom. |
Pauli Exclusion Principle | In a given atom, no two electrons can occupy the same atomic orbital and have the same spin. |
Electron Configuration | The arrangement of electrons in an atom. |
Valence Electron | The electron in the outermost principal energy level of an atom. |
Core Electron | An inner electron; an electron not in the outermost principal energy level of an atom. |
Bond | The force that holds two or more atoms together and makes them function as a unit. |
Bond Energy | The energy required to break a given chemical bond. |
Ionic Bonding | The attraction between oppositely charged ions. |
Ionic Compound | A compound that results when a metal reacts with a nonmetal to form cations and anions. |
Polar Covalent Bond | A covalent bond in which the electrons are not shared equally because one atom attracts the shared electrons more than the other atom. |
Electronegativity | The tendency of an atom in a molecule to attract shared electrons to itself. |
Dipole Moment | A property of a molecule in which the charge distribution can be represented by a center of positive charge and the center of negative charge. |
Lewis Structure | A representation of a molecule or polyatomic ion showing how valence electrons are arranged among the atoms in the molecule or ion. |
Single Bond | A covalent or polar covalent bond in which one pair of electrons is shared by two atoms. |
Double Bond | A covalent or polar covalent bond in which two pairs of electrons are shared by two atoms. |
Triple Bond | A covalent or polar covalent bond in which three pairs of electrons are shared by two atoms. |
Barometer | A device that measures atmospheric pressure. |
Absolute Zero | -273 Degrees Delicious |
Charles's Law | The volume of a given sample of a gas is directly related to the temperature of the gas at constant pressure. V=bT |
Ideal Gas Law | PV= nRT |
Ideal Gas | A hypothetical gas that exactly obeys the ideal gas law. |
Partial Pressure | The independent pressure exerted by a gas in a mixture of gases. |
Dalton's Law of Partial Pressure | For a mixture of gases in a container, the total pressure exerted is the sum of the partial pressures of each of the gases. |
Molar Volume | The volume of 1 mole of an ideal gas is equal to 22.4 L at 0 degrees Celsius and 1 atm. |
Intermolecular Forces | Attractive forces that occur between molecules. |
Intramolecular Forces | Attractive forces that occur between atoms in a molecule; chemical bonds. |
Normal Boiling Point | The boiling temperature of a liquid under one atmosphere of pressure. The temperature at which the vapor pressure of a liquid is exactly one atmosphere. |
Normal Freezing Point | The freezing temperature of a liquid under one atmosphere of pressure. |
Vaporization | The process in which a liquid in converted into a gas. |
Condenstation | The process in which a vapor is converted into a liquid. |
Vapor Pressure | The pressure exerted by a vapor in equilibrium with its liquid phase at a certain temperature. |
Molecular Solid | A solid composed of molecules. |
Atomic Solid | A solid that contains atoms at the lattice points. |
Alloy | A substance that contains a mixture of elements and has metallic properties. |
Solution | A homogeneous mixture. |
Solvent | The dissolving medium in a solution. |
Solute | The substance dissolved in the solvent to make a solution. |
Aqueous Solution | A solution with water as a solvent. |
Saturated | Describes a solution that contains as much solute as will dissolve at that temperature. |
Unsaturated | Describes a solution in which more solute can dissolve than is dissolved already at that temperature. |
Supersaturated | Describes a solution that contains more solute than a saturated solution will hold at that temperature. |
Concentrated | Describes a solution in which a relatively large amount of solute is dissolved in a solution. |
Dilute | Describes a solution in which a relatively small amount of solute is dissolved in a solution. |
Standard Solution | A solution in which the concentration is accurately known. |
Dilution | The process of adding a solvent to a solution to lower the concentration of a solute. |
Neutralized Reaction | An acid-base reaction. |
Equivalent Weight | The mass (in grams) of one equivalent of an acid or a base. |
Colligative Property | A property that is dependent only on the number of solute particles present in a solution. |
Acid | A substance that produces hydrogen ions in a solution; proton donor. |
Base | A substance that produces hydroxide ions in a solution; a substance that accepts protons. |
Arrhenius Concept of Acids and Bases | Acids produce hydrogen ions in a solution; bases produce hydroxide ions in a solution. |
Conjugate Acid | The substance formed when a proton is added to a base. |
Conjugate Base | The remaining substance when a proton is lost from an acid. |
Strong Acid | An acid that completely dissociates to produce H+ ions in a solution. |
Weak Acid | An acid that dissociates to a slight extent in aqueous solution. |
Amphoteric Substance | A substance that can behave either as an acid or as a base. |
Indicator | A chemical that changes color depending on the pH of a solution. |
pH Meter | A device used to measure the pH of a solution. |
Titration | A technique in which a solution of known concentration is used to determine the concentration of another solution. |
Equivalence Point | The point in a titration when enough titrate has been added to react exactly with the substance in solution that is being titrated. |
Titrated Curve | A plot of pH of solution versus volume of titrant added to a given solution. |
Buffered Solution | A solution that resists a change in pH when wither an acid or a base are added. |