Question

Write the chemical equation for the reactions of chlorine with (i) sulphur dioxide, and (ii) turpentine oil.

Hint:

Turpentine oil is often used as a qualitative test for chlorine gas since it produces dense white fumes on reaction.

Answer 1

(i) Reaction of chlorine with sulphur dioxide:
When chlorine reacts with sulphur dioxide in the presence of water, sulphuric acid and hydrochloric acid are formed. \[ Cl_2 + SO_2 + 2H_2O \longrightarrow H_2SO_4 + 2HCl \] (ii) Reaction of chlorine with turpentine oil:
Chlorine reacts violently with turpentine oil (a mixture of terpenes) producing fumes. This reaction is used in the laboratory as a test for chlorine gas. \[ Cl_2 + \text{Turpentine oil} \longrightarrow \text{Chlorinated products (with dense fumes)} \] Conclusion:
- With sulphur dioxide, chlorine forms sulphuric acid and hydrochloric acid.
- With turpentine oil, chlorine gives a vigorous reaction producing white fumes.