Concentrated aqueous sodium chloride can be electrolysed in the laboratory using graphite electrodes.

a. Write the formulae for all the ions present in an aqueous solution of sodium chloride.

b. Write half-equations to show the reactions at:

i. The anode (positive electrode)

ii. The cathode (negative electrode).

c. Explain why the reaction at the anode is classed as oxidation.

d. After a while, the solution near the cathode becomes very alkaline. Explain why.

e. The chlorine produced at the anode can react with warm concentrated sodium hydroxide: 

Cl₂ + 6NaOH 5NaCl + NaClO₃ + 3H₂O

What are the oxidation number changes per atom of chlorine when

i. Cl₂ is converted to NaCl?

ii. Cl₂ is converted to NaClO₃?

f. Give the systematic name for the compound NaClO₃.