Acids, alkalis & pH

The pH scale describes solutions in water.

ACIDIC: below 7

NEUTRAL: 7

ALKALINE: above 7

At room temperature, pure water is neutral.

Universal indicator changes colour. Use its colour chart. Examples: pH 2 is red, pH 7 is green, and pH 12 is purple. Other pH values give other colours.

NEUTRALISATION

Acid + metal hydroxide → salt + water

Example: hydrochloric acid + sodium hydroxide → sodium chloride + water

Never taste laboratory solutions.