Grade 12 chemistry - Acid-Base Equilibrium

Arrhenius theory

A theory stating that, in an aqueous solution, an acid is a substance that produces hydrogen ions and a base is a substance that produces hydroxide ions

Brønsted-Lowry theory

A theory stating that an acid is a hydrogen ions (proton) donor and a base is a hydrogen ion (proton) acceptor

Hydronium ion

A water molecule that has accepted a hydrogen ions, H₃O⁺

Conjugate acid

The substance that forms when a base, according to the Brønsted—Lowry theory, accepts a hydrogen ion (proton)

Conjugate base

The substance that forms when an acid loses a hydrogen ion (proton)

Conjugate acid-base pair

Two substances related to each other by the donating and accepting of a single hydrogen ion

Amophiprotic (amphoteric)

Able to donate or accept a hydrogen ion (proton) and thus act as both a Brønsted—Lowry acid and a Brønsted—Lowry base

Acid ionization constant

The equilibrium constant for the ionization equation f an acid; also called acid dissociation constant

Strong acid

An acid that ionizes almost 100% in water, producing hydrogen ions

Weak acid

An acid that only partly ionizes in water, producing hydrogen ions

Oxyacid

An acid in which the acidic hydrogen atom is attached to an oxygen atom

Organic acid

An acid (except carbonic acid, H₂CO_3). Containing carbon, oxygen, and hydrogen atoms; also called carboxylic acid

Strong base

A base that dissociates completely in water, producing hydroxide ions

Weak base

A base that only partially reacts with water to produce hydroxide ions

Base ionization constant

The equilibrium constant for the ionization of a base; also called the base dissociation constant

Organic base

An organic compound that increases the concentration of hydroxide ions in aqueous solution

Auto ionization of water

The transfer of a hydrogen ion from one water molecule to another

Ion-product constant for water

The equilibrium constant for the auto ionization of water

Ion-product constant for water

The equilibrium constant for the autoionization of water

pH

The negative logarithm of the concentration of hydrogen ions in an aqueous solution

pOH

The negative logarithm of the concentration of hydroxide ions in an aqueous solution

pH meter

A device that measures the acidity or alkalinity of a solution electronically and displays the result as a pH value

Percentage ioni

Monoprotic acid

An acid that possesses only one ionizable (acidic) hydrogen atom

Polyprotic acid

An acid that possessesmore than one ionizable (acidic) hydrogen atom

Hydrolysis

A chemical reaction of an ion with water to produce an acidic or basic solution by the production of hydronium or hydroxide ions

Titration

The addition of precise volumes of a solution in a burette to a measured volume of a sample solution; often used to determine the concentration of a substance in the sample

Sample

The solution being analyzed in a titration

Titrant

The solution in a burette during a titration

Burette

A calibrated tube used to deliver variable known volumes of a liquid during a titration

Standard solution

A solution whose concentration is accurately and precisely known

Primary standard

A highly pure and stable chemical used to determine the precise concentration of acids or bases

Equivalence point

The point in a titration when neutralization is complete

Endpoint

The point in a titration at which a sharp change in a measurable and characteristic property occurs (for example, a colour change in an acid—base indicator)

pH curve

A graph of pH plotted against volume of titration added in an acid—base titration; titration curve

Buffering capacity

The ability of a buffer to resist changes in pH by reacting with added hydrogen ions or hydroxide ions