General Chemistry Flashcards
Concentration of a solution calculated by gram equivalent weight of solute per liter of solution, often denoted by N.
Normality
A solution of unknown concentration to which small volumes of a solution of known concentration are added to reach the equivalence point.
Titrand
The measure of how quickly reactants are consumed and products are formed, commonly expressed in terms of mol L^‐1 s^‐1.
Reaction Rate
An equation used to determine a cell’s electromotive force (emf) when conditions are not standard. E{cell} = E°{cell} - (0.0592/n)logQ where E{cell} is the emf, E°{cell} is the emf under standard conditions, n is the number of electrons transferred in the oxidation-reduction reaction, and Q is the reaction quotient.
Nernst Equation
The resulting positive nuclear charge an outer electron senses after accounting for the shielding effect of inner core electrons. Abbreviated Z{eff}. Increases from left to right and from bottom to top on the Periodic Table.
Effective Nuclear Charge
The amount of energy required to remove an electron from orbit about a gaseous atom into free space. Increases from left to right and from bottom to top on the Periodic Table.
Ionization Energy
A hypothetical equation showing only the species that is oxidized or reduced in a oxidation-reduction reaction and the correct number of electrons transferred between the species in the complete, balanced equation.
Oxidation-Reduction Half-Reaction
A reaction that will proceed or occur on its own without additional energy input from its surroundings.
Spontaneous Reaction
A unification of Boyle’s Law, Charles’s Law, Gay-Lussac’s law, and Avogadro’s principle into the formula that describes the behavior of ideal gases: PV = nRT.
Ideal Gas Law
The electrode where oxidation occurs during a cell’s oxidation-reduction reaction. Electrons always flow from the anode in an electrochemical cell.
Anode
A transfer of energy from a substance with a higher temperature to a substance with a lower temperature.
Heat
The product of the molar concentrations of dissociated ions in solution at any point in a dissociation reaction, where each ion is raised to the power of its stoichiometric coefficient. Denoted IP.
Ion Product
An apparatus commonly referred to as a bomb calorimeter; used to measure the amount of heat absorbed or released during a reaction.
Constant-Volume Calorimeter
An equation commonly used in titration-based problems that relates the pH or pOH of a solution to the pKₐ and the ratio of the dissociated species. pH = pKₐ + log([A^-]/[HA]).
Henderson-Hasselbalch Equation
The sum of all the masses present (in amu) in one molecule of a molecular compound.
Molar Mass
The reactant in a chemical equation that, given nonstoichiometric amounts, determines the amount of product that can form; the reactant that runs out first.
Limited Reagent
A reactant in which an acid and a base are combined to form a salt (and often water as well).
Neutralization Reaction
The point in a titration at which an equimolar amount of titrant has been added to the unknown solution.
Equivalence Point
The energy released when an atom or ion in the gaseous state gains an electron. Increases from left to right and from bottom to top on the Periodic Table.
Electron Affinity
The ratio of the amount of solute to the amount of solution; quantified by mole fraction, molarity, molality, or normality, among other measures.
Concentration
States that the partial pressure of a gas dissolved in a solution is directly proportional to the partial pressure of this gas above the solution.
Henry’s Law
The sum of the exponents in a rate law, where each exponent provides the reaction order with respect to its reactant.
Reaction Order
A process in which temperature (and, therefore, internal energy) remain constant.
Isothermal Process
Common definition of acids as proton (H^+) donors and bases as proton acceptors.
Brønsted-Lowry Definition
A reaction in which two or more reactants combine to form a product (such as A + B ➝ C).
Combination Reaction
A medium, commonly a liquid, into which a solute is dissolved to create a solution.
Solvent
The energy barrier that must be overcome for a reaction to proceed; often denoted by Ea.
Activation Energy
A system that allows for the exchange of energy and matter across its boundaries.
Open System
A pressure-temperature plot showing the conditions under which a substance exists in pure phase or in equilibrium between different phases.
Phase Diagram
A solution containing water as its solvent.
Aqueous Solution
An analytical procedure in which a solution of known concentration is slowly added to a solution of unknown concentration to the point of molar equivalency, thereby providing the concentration of the unknown solution.
Titration
The charge assigned to an atom in a molecule or polyatomic ion, assuming even division of the electrons in a bond. Molecules containing atoms with lower formal charges tend to be more stable than those with higher formal charges.
Formal Charge
A system that can exchange neither energy nor matter with its surroundings.
Isolated System
An electrochemical cell that uses an external electric source to drive a nonspontaneous (unfavorable) oxidation-reduction reaction.
Electrolytic Cell
The highly reactive elements found in Group IA (Group 1) of the Periodic Table, except hydrogen.
Alkali Metals
The electrons occupying the outermost electron shell of an atom that participate in chemical bonds. Atoms with the same number of valence electrons usually have similar properties.
Valence Electrons
A chemical reaction in which an atom or ion of one compound is replaced by another atom or ion (such as A + BC ➝ B + AC).
Single-Displacement Reaction
States that the enthalpy change of an overall reaction is equal to the sum of the standard heats of formation of the products minus the sum of the standard heats of formation of the reactants.
Hess’s Law
Law stating that energy cannot be created or destroyed but only transferred and transformed.
Law of Conservation of Energy
An electrode immersed in an electrolytic solution that is the site of either oxidation or reduction in an electrochemical cell.
Half-Cell
Elements that have characteristically high electronegativity, ionization energy, and electron affinity. These elements tend to be found on the right side of the Periodic Table and are poor conductors of electricity.
Nonmetals
A single particle or polyatomic species with an electric charge.
Ion
The region in a molecule where atomic orbitals overlap, resulting in either a stable low-energy bonding orbital or an unstable high-energy antibonding orbital.
Molecular Orbital
The point in a titration at which exactly half the molar equivalence of reactant is consumed by the titrant being added. At this point in an acid-base titration, the pH is equal to the pKₐ of the titrand.
Half-Equivalence Point
The distance measured either between the nucleus and outermost electron of an atom or by the separation of the two nuclei in a diatomic element. Decreases from left to right and from bottom to top on the Periodic Table.
Atomic Radius
Elements found in Group IIA (Group 2) of the Periodic Table.
Alkaline Earth Metals
A system that allows for the exchange of energy, but not matter, across its boundaries.
Closed System
The acronym for valence shell electron pair repulsion theory, which states that the three-dimensional molecular geometry about some central atom is determined by the electronic repulsion between its bonding and nonbonding electron pairs.
VSEPR Theory
A reaction in which a species loses electrons.
Oxidation
A point on a phase diagram at which a substance exists in equilibrium between all three phases.
Triple Point
Inert elements naturally existing in a gaseous state that comprise Group VIII (Group 18) of the Periodic Table.
Noble Gas
A solution of known concentration added in small volumes to a solution of unknown concentration to reach the equivalence point.
Titrant
The pressure contribution of a single gas in a container holding a mixture of gases, as given by the equation P{A} = X{A}P{total}, where X{A} is the mole fraction of gas A and P{total} is the total pressure of the mixture.
Partial Pressure
273 Kelvin (0° Celsius) and 1 atmosphere (760 mmHg).
Standard Temperature and Pressure (STP)
An acid that will completely dissociate in aqueous solution (such as HCl, HI, HNO3, and HClO4).
Strong Acid
A representation of a displacement reaction showing only the reactive species and omitting the spectator ions.
Net Ionic Reaction
Concentration of a solution calculated by moles of solute per kilograms of solvent, often denoted by m.
Molality