Acids, Bases and Salts Vocabulary Flashcards

A comprehensive set of vocabulary flashcards based on the 'Acids, Bases and Salts' lecture notes, covering definitions of chemical terms, indicators, and salt types.

pH scale

A scale used to measure the strength of an acid or a base, ranging from $0$ to $14$.

Potenz

The German word meaning power, which the 'p' in pH stands for.

Acidic solution

A solution with a pH less than $7$.

Basic solution

A solution with a pH more than $7$.

Neutral solution

A solution with a pH equal to $7$, showing no acidic or basic properties.

Universal indicator

A substance that shows a change of colour over a range of pH and is often available as pH paper.

Organic acids

Weak acids present in plants and animals, such as citric acid, lactic acid, and malic acid.

Mineral acids

Strong acids prepared artificially in industries, such as $H_2SO_4$, $HCl$, and $HNO_3$.

Concentrated acid

A solution that contains a large amount of the acid.

Dilute acid

A solution that contains a small amount of the acid.

Oxyacids

Acids that contain both hydrogen and oxygen, such as nitric acid ($HNO_3$) and phosphoric acid ($H_3PO_4$).

Hydracids

Acids which contain hydrogen and non-metallic elements other than oxygen, such as hydrochloric acid ($HCl$).

Basicity of an acid

The number of replaceable hydrogen atoms present in a molecule of the acid.

Bases

Oxides or hydroxides of metals that taste bitter, feel slippery to touch, and neutralise acids.

Alkalis

Bases that are soluble in water, such as sodium hydroxide ($NaOH$) and potassium hydroxide ($KOH$).

Acidity of a base

The number of replaceable hydroxyl ($OH$) ions in a base.

Indicator

Special substances used to test the acidic or basic nature of a substance by changing colour.

Litmus

The most common natural indicator obtained from lichens, turning red in acid and blue in base.

Neutralisation reaction

A reaction where an acidic solution and a basic solution mix to produce a salt, water, and heat.

Salt

A substance formed by neutralisation with a metal part from the base and a non-metal part from the acid.

Normal salts

Salts formed by complete neutralisation that do not contain any replaceable $H$ or $OH$ group.

Acidic salts

Salts formed by incomplete neutralisation of an acid by a base that contain replaceable $H$ atoms.

Basic salts

Salts formed by incomplete neutralisation of a base by an acid that contain replaceable $OH$ groups.

Water of crystallisation

The fixed number of water molecules that remain with a crystalline salt.

Hydrated salts

Salts that have a fixed number of water molecules as part of their structure, such as $CuSO_4.5H_2O$.

Deliquescent salts

Soluble salts that absorb moisture from the atmosphere and become wet, such as sodium nitrate.

Efflorescent salts

Hydrated salts which lose their water of crystallisation upon exposure to the atmosphere.