1.1. Hydrogen, chlorine and sodium hydroxide are commercially important chemicals which can all be made in one process. 

The process involves passing electricity through an aqueous solution of sodium chloride (brine). 

Figure 2 shows an electrolytic cell in which this process can be carried out.

Figure 2 

Identify the substances produced at points A, B and C.

A _________________________

B _________________________

C _________________________

1.2. Complete and balance the equations for the reactions at the electrodes.

___Cl^– – ___e^– → Cl₂ ___H + ___e^– → H₂

1.3. Identify the compound in the cell responsible for producing the hydrogen ions.

1.4. What kind of particles must be able to pass through the barrier so that electrolysis can take place?