question_answer

Direction for: In each of the following questions a statement of Assertion is given followed by a corresponding statement of Reason just below it. Of the statements mark the correct answer as

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.

A)  If both assertion and reason are true and reason is not the correct explanation of assertion.

B)  If both assertion and reason are true but reason is not the correct explanation of assertion.

C)  If assertion is true but reason is false.

D)  If both assertion and reason are false

Correct Answer: D

Solution :

Both the assertion and reason are false. Sb (III) is placed in II group in qualitative analysis where it is precipitated in acidic medium so that radicals of higher groups may not get precipitated. In alkaline medium \[{{\text{H}}_{\text{2}}}\text{S}\] ionises upto greater extent and thus Sb (III) can also precipitate in basic medium.