Grade 12 Physical Sciences - Acids and Bases Vocabulary

A set of vocabulary flashcards for Grade 12 Physical Sciences covering core concepts, theories, and definitions of acids and bases.

Arrhenius Acid

A substance that produces hydrogen ions ($H^+$) in solution.

Arrhenius Base

A substance that produces hydroxide ions ($OH^-$) in solution.

Lowry-Brønsted Acid

A substance that donates a hydrogen ion ($H^+$) or proton donor.

Lowry-Brønsted Base

A substance that accepts a hydrogen ion ($H^+$) or proton acceptor.

Strong Acid

An acid that ionises completely in water to form a high concentration of hydronium ions ($H_3O^+$), characterized by $K_a > 1$ and a $pH$ between $0$ and $3$.

Weak Acid

An acid that ionises incompletely in water to form a low concentration of hydronium ions ($H_3O^+$), characterized by $K_a < 1$ and a $pH$ between $4$ and $6$.

Strong Base

A base that dissociates completely in water to form a high concentration of hydroxide ions ($OH^-$), characterized by $K_b > 1$ and a $pH$ between $11$ and $14$.

Weak Base

A base that dissociates incompletely in water to form a low concentration of hydroxide ions ($OH^-$), characterized by $K_b < 1$ and a $pH$ between $7$ and $10$.

Monoprotic Acid

An acid that can donate one proton ($H^+$) per molecule.

Diprotic Acid

An acid that can donate two protons ($H^+$) per molecule.

Concentrated Acid or Base

A solution that contains a high ratio of solute to volume of solvent, where little or no water is added.

Dilute Acid or Base

A solution where acid or base has been added to water, resulting in a low concentration of solute per volume of solvent.

Ampholyte

A substance that can act as both an acid and a base in different reactions.

Conjugate Base

The species formed when an acid donates a proton ($H^+$).

Conjugate Acid

The species formed when a base accepts a proton ($H^+$).

Hydrolysis

The reaction of a salt with water, which can break bonds and cause the resulting solution to become acidic or basic.

Equivalence Point

The point in a titration at which the acid/base has completely reacted with the base/acid.

Endpoint

The point in a titration where the indicator changes colour.

Standard Solution

A solution of known concentration.

Auto-ionisation Constant of Water ($K_w$)

The equilibrium constant for the ionisation of water, given by $K_w = [H_3O^+][OH^-] = 1.00 \times 10^{-14}$ at $25\,^{\circ}\text{C}$ ($298\,\text{K}$).