Assertion : Sb (III) is not precipitated as sulphide when in its alkaline solution `H_(2)S` is passed.
Reason : The concentration of `S^(2-)` ion in alkaline medium is inadequate for precipitation.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If the assertion and reason both are false.

Answer

C

Explanation

Sb (III) comes under II group. The group reagent for this group is`H_(2)S` in HCl . These radicals are precipitated as their sulphide where as sulphide of other metals remain in the solution because of their high solubility product, HCl act as a source of `H^(+)` ion and thus decreases the concentration of `S^(2-)` ion (common ion effect ) So the decreased concentration of `S^(2-)` is sufficient to precipitate the II group metals due to their ow `K_(sp)` value.