Equilibrium: an equilibrium in which opposing changes to a closed chemical system occur simultaneously at the same rate
Homogeneous Equilibrium: an equilibrium in which all the reactants and the products in the system are in the same phase
Heterogeneous Equilibrium: an equilibrium in which reactants and products in the chemical system are in different phases; an example is a solution containing a crystal of solute
Favourable Change: a change that has a tendency to occur naturally under certain conditions
Entropy (S): a measure of the energy that spreads out during a process
Second law of thermodynamics: the law stating that the total entropy of the universe is increasing
Free Energy: available energy; a measure of the useful work that can be obtained from a reaction
Law of chemical equilibrium: the law stating that there is a constant ratio, at equilibrium, between the
concentrations of products and reactants
Equilibrium Constant (Keq): the ratio of the forward rate constant, Kf, divided by the reverse rate constant, Kr; also a ratio of products over reactants
ICE Table: a problem-solving table that shows the initial conditions, the change, and the equilibrium conditions
Reaction Quotient (Qc): an expression that is identical tothe equilibrium constant expression but is calculated using concentration values that are not necessarily those at equilibrium
Le Châtelier’s principle: the principle stating that a dynamic equilibrium tends to respond so as to relieve the effect of any change in the conditions that affect the equilibrium
Common Ion Effect: the effect on a system at equilibrium when a surplus of one of the reactant ions is added to the system; an application of Le Châtelier’s principle
Hydronium Ion: an aqueous hydrated proton, H3O+
Conjugate acid-base pair: an acid and a base that differ by one proton
Monoprotic acids: an acid that has one hydrogen atom that dissociates in water
Polyprotic acids: an acid that has more than one hydrogen atom that dissociates in water
Ion product constant for Water (Kw): the product of the concentration of the hydronium ions and the hydroxide ions in a solution ([H3O+][OH−]); always equal to 1.0 × 10^(−14) at 25°C
pH: the logarithm of the hydronium ion concentration
pOH: the logarithm of the hydroxide ion concentration
Acid dissociation constant (Ka): the equilibrium constant for the ionization of a weak acid in water, giving the hydronium ion and the conjugate base of the acid
Buffer Solution: a solution that resists changes in pH when moderate amounts of acid or base are added
Buffer Capacity: the amount of acid or base that can be added to a solution before significant change occurs to the pH of the solution
Acid-Base Titration curve: the graph for an acid-base titration, in which the pH of an acid (or base) is plotted versus the volume of the base (or acid) added
Equivalence Point: the point in a titration when just enough acid and base have been mixed so that a complete reaction occurs and there is no excess of either reactant
End-point: the point in a reaction when an indicator changes colour; occurs over a range of about 2 pH units
Solubility Product Constant (Ksp): the product of the concentrations of the ions of an ionic compound in aqueous solution at 25°C
Ion product (Qsp): an expression that is identical to the solubility product constant, but its value is calculated using concentrations that are not necessarily those at equilibrium
Fractional Precipitation: a process by which ions are selectively precipitated from solution, leaving other ions still dissolved
Qualitative Analysis: the branch of analytical chemistry that involves identifying elements, compounds, and ions in samples of unknown or uncertain composition
Quantitative Analysis: the branch of analytical chemistry that involves determining how much of a compound, element, or ion is in a sample
Homogeneous Equilibrium: an equilibrium in which all the reactants and the products in the system are in the same phase
Heterogeneous Equilibrium: an equilibrium in which reactants and products in the chemical system are in different phases; an example is a solution containing a crystal of solute
Favourable Change: a change that has a tendency to occur naturally under certain conditions
Entropy (S): a measure of the energy that spreads out during a process
Second law of thermodynamics: the law stating that the total entropy of the universe is increasing
Free Energy: available energy; a measure of the useful work that can be obtained from a reaction
Law of chemical equilibrium: the law stating that there is a constant ratio, at equilibrium, between the
concentrations of products and reactants
Equilibrium Constant (Keq): the ratio of the forward rate constant, Kf, divided by the reverse rate constant, Kr; also a ratio of products over reactants
ICE Table: a problem-solving table that shows the initial conditions, the change, and the equilibrium conditions
Reaction Quotient (Qc): an expression that is identical tothe equilibrium constant expression but is calculated using concentration values that are not necessarily those at equilibrium
Le Châtelier’s principle: the principle stating that a dynamic equilibrium tends to respond so as to relieve the effect of any change in the conditions that affect the equilibrium
Common Ion Effect: the effect on a system at equilibrium when a surplus of one of the reactant ions is added to the system; an application of Le Châtelier’s principle
Hydronium Ion: an aqueous hydrated proton, H3O+
Conjugate acid-base pair: an acid and a base that differ by one proton
Monoprotic acids: an acid that has one hydrogen atom that dissociates in water
Polyprotic acids: an acid that has more than one hydrogen atom that dissociates in water
Ion product constant for Water (Kw): the product of the concentration of the hydronium ions and the hydroxide ions in a solution ([H3O+][OH−]); always equal to 1.0 × 10^(−14) at 25°C
pH: the logarithm of the hydronium ion concentration
pOH: the logarithm of the hydroxide ion concentration
Acid dissociation constant (Ka): the equilibrium constant for the ionization of a weak acid in water, giving the hydronium ion and the conjugate base of the acid
Buffer Solution: a solution that resists changes in pH when moderate amounts of acid or base are added
Buffer Capacity: the amount of acid or base that can be added to a solution before significant change occurs to the pH of the solution
Acid-Base Titration curve: the graph for an acid-base titration, in which the pH of an acid (or base) is plotted versus the volume of the base (or acid) added
Equivalence Point: the point in a titration when just enough acid and base have been mixed so that a complete reaction occurs and there is no excess of either reactant
End-point: the point in a reaction when an indicator changes colour; occurs over a range of about 2 pH units
Solubility Product Constant (Ksp): the product of the concentrations of the ions of an ionic compound in aqueous solution at 25°C
Ion product (Qsp): an expression that is identical to the solubility product constant, but its value is calculated using concentrations that are not necessarily those at equilibrium
Fractional Precipitation: a process by which ions are selectively precipitated from solution, leaving other ions still dissolved
Qualitative Analysis: the branch of analytical chemistry that involves identifying elements, compounds, and ions in samples of unknown or uncertain composition
Quantitative Analysis: the branch of analytical chemistry that involves determining how much of a compound, element, or ion is in a sample