Sometimes yellow turbidity appears while passing `H_(2)S` gas even in the absence of II group radicals. This is because of

Options

A. Sulphur is present in the mixture as an impurity
B. The fourth group radicals are precipitated as sulphides
C. The `H_(2)S` is oxidized by some acid radicals
D. The third group radicals are precipitated

Answer

C

Explanation

This is due to the precipitation of fourth group radical as sulphides due to high concentration of `S^(2-)` in the solution as a result yellow turbidity is obtained.