question_answer

Directions : In the following question more than one of the answers given may be correct. Select the correct answer and mark it according to the code:

Excess of\[KI\]reacts with\[CuS{{O}_{4}}\]solution and then\[N{{a}_{2}}{{S}_{2}}{{O}_{3}}\]solution is added to it. The correct statements for this reaction are (1) \[C{{u}_{2}}{{I}_{2}}\]is formed (2)\[Cu{{I}_{2}}\]is formed (3)\[N{{a}_{2}}{{S}_{2}}{{O}_{3}}\]is oxidised (4) evolved\[{{I}_{2}}\]is oxidised.

A)  1, 2 and 3 are correct.

B)  1 and 2 are correct.

C)  2 and 4 are correct.

D)  1 and 3 are correct.

Correct Answer: D

Solution :

                 \[CuS{{O}_{4}}+KI\xrightarrow[{}]{{}}\underset{unstable}{\mathop{Cu{{I}_{2}}}}\,+{{K}_{2}}S{{O}_{4}}\] \[Cu{{I}_{2}}\xrightarrow{{}}C{{u}_{2}}{{I}_{2}}+{{I}_{2}}\] In this reaction\[C{{u}_{2}}{{I}_{2}}\]and\[{{I}_{2}}\]are formed.\[{{I}_{2}}\] reacts with hypo and oxidised it.