Chemistry: Acids and Alkalis Revision

Acids

Bases

Examples:

A Substance that when dissolved in water forms H+ Ions

Hydrochloric Acid - HCL

Nitric - HNO3

Sulphuric Acid - H2SO4

Ethanoic (Acetic) Acid - CH3COOH

Alkalis

Examples:

Caustic Soda (Sodium Hydroxide) - NaOH

Ammonium Hydroxide - NH4OH

Calcium Hydroxide - Ca(OH)2

Indicators

pH Scale

Acids - Less than 7

Alkalis - More than 7

Neutral - 7

Gradual Change

Instant Change

A soluble base

Substances that neutralise acids

Neutral

Universal Indicator

Methyl Red

Methyl Orange

Phenolphthalein

Litmus

Conduction

Both acids and alkalis conduct electricity because they form ions when dissolved in water (electrolytes).

A compound that when dissolved in water does not produce H+ or OH- Ions or produces equal amounts of both.

Reactions

Neutralisation Reaction

Acid + Alkali --> Water + Salt

Electrolysis of an acid

Hydrogen at Cathode

Other Compound at Anode

Titration

The testing for the concentration of an unknown acid or alkali

Key Formula:

Moles = Concentration x Volume

Apparatus:

Pipette

Burette

Conical Flask

Below 0 - Above 14

Acids = Colourless

Bases = Pink

A mix of Several Indicators inducing gradual colour change

Red = Less than 3 pH

Orange / Yellow = 3 - 6 pH

Green = 7 pH

Blue = 8 - 11 pH

Violet = Greater than 11 pH

Examples:

Water

Human blood