C4

Question 1

Oxidation and reduction

Answer 1

Oxidation is loss of electrons
Reduction is gain of electrons

OILRIG

Question 2

Equation for reactions of acids

Answer 2

Metal + acid 🡪 salt + hydrogen

Question 3

Indicators

Answer 3

Indicators are substances which change colour

when you add them to acids and alkali.

Question 4

Where do pos and neg ions go in electrolysis

Answer 4

Positive ions go to negative electrode (cathode) and are reduced (gain of electrons).

Negative ions go to the positive electrode (anode) and are oxidised (loss of electrons).

Ions are discharged at the electrodes producing elements. This is called electrolysis.