S2 Unit 2 chemistry terms

acid

A substance with a pH less than seven

acid dissociation constant

The equilibrium constant, Ka, for the disassociation of an acid. A strong acid has a higher acid dissociation constant than a weak acid.

Base

A substance with a pH greater than seven

base disassociation constant

The equilibrium constant, Kb, for the dissociation of a base. A strong base has a larger base dissociation constant than a weak base.

dissociate

To separate a compound into its ions in water

dynamic equilibrium

A state or condition in which the forward and reverse directions of a reversible process occur at the same rate

equilibrium

A state of a chemical reaction in which both forward and reverse reactions proceed at equal rates

equilibrium constant

This is Keq for a reaction. It is equal to the concentration of products divided by the concentration of reactants, and is always the same at a given temperature and pressure.

hydroxide

The base ion OH^-

Ka

The acid dissociation constant or the equilibrium constant for an acid. Ka is equal to the concentration of products divided by the concentration of reactants. A strong acid as a higher acid dissociation constant than a weak acid.

Kb

The base dissociation constant, or the equilibrium constant for a base. Kb is equal to the concentration of products divided by the concentration of reactants in a reaction that involves a base dissociation. A strong base as a higher dissociation constant than a weak base.

Keq

The equilibrium constant for a reaction. Keq is equal to the concentration of products divided by the concentration of reactants. it is always the same at a given temperature and pressure.

Le Châtelier’s principle

A principal stating that if a chemical reaction at equilibrium is disturbed, the reaction will move in the direction that minimize the effect of the disturbance.

strong acid

An acid that dissociates completely into ions in solution.

strong bases

Bases that disassociate completely into ions in solution.

triple point

The temperature and pressure at which the three phases of a substance coexistent in equilibrium.

weak acid

An acid that does not dissociate completely into ions in solution

weak bases

bases that do not dissociate completely into ions in solution.

Acid Rain

Rainwater with high acidity due to air pollutants, especially those released by burning fossil fuels

Acid base reaction

Any chemical reaction between an acid and a base that results in a neutral solution of water and a salt

Arrhenius acid

A substance that produces hydrogen ions when dissolved in water

Arrhenius base

A substance that produces hydroxide ions when dissolved in water

Bronsted Lowry acid

A proton donor

Buffer

A solution that resists changes in pH

conjugate acid

The form of base takes after it gains a hydrogen ion(or proton)

conjugate acid base pair

The species that is formed when a base gains a hydrogen ion (or proton)

Conjugate base

The form an acid takes after it loses a hydrogen atom (or proton)

Lewis acid

An electron pair accepter.

Lewis base

An electron pair donor

neutralization reaction

A reaction in which an acid and a base react to form water and a salt

pH

A measure of the hydrogen ion concentration of a substance that indicates how acidic or basic a solution is. pH=-log[H+]

pH scale

A scale that indicates the acidity of a solution; it is based on the concentration of hydrogen ions.

pOH

A measurement of the OH- concentration in a substance: pOH = 14-pH

Salt

Any ionic compound that doesn’t contain H+ plus or OH- minus