When H2S is passed into a solution of iron (III) chloride; the solution turns?

A. Pale green
B. Pale red
C. Brown
D. Colourless

Correct Answer:

Option A – Pale green

Explanation

A reaction between Iron (iii) chloride and Hydrogen sulphide leads to the reaction

2FeCl3(aq) + H2S(g) → 2FeCl2(aq) + 2HCl(aq) + S(s)

The colour change is from REDDISH BROWN to PALE GREEN.