Question

Assertion: Auric Chloride $ {\text{AuC}}{{\text{l}}_{\text{3}}} $ cannot be stored in a vessel made up of copper, iron, nickel, chromium, zinc, or tin.
Reason: Gold is a very precious metal
(A) Both assertion and Reason are correct and the reason is the correct explanation of the assertion.
(B) Both assertion and Reason are correct but the reason is not the correct explanation of the assertion.
(C) Assertion is correct but the reason is incorrect.
(D) Both the Assertion and the reason are incorrect.

Answer 1

Hint: The reactivity of the elements depend on the position of the elements in the electrochemical series. The higher an element is placed in the series, higher will be the oxidation potential and the lower it is placed, higher will be the reduction potential.

Complete step by step solution
The reduction potential of any element can be defined as the ability of the element to acquire electrons and get reduced whereas the oxidation potential measures the ability of the element to lose electrons. As per the electrochemical series of elements, those at the top of the series have higher tendency to get oxidised themselves or lose electrons than those at the bottom of the group. Gold comes after copper, iron, nickel, chromium, zinc, or tin in the electrochemical series and hence it has the tendency to be reduced by any of these elements to form metallic gold after accepting electrons from them so that they are oxidized and the Auric Chloride is reduced to metallic gold.
Hence, Auric Chloride $ {\text{AuC}}{{\text{l}}_{\text{3}}} $ cannot be stored in a vessel made up of copper, iron, nickel, chromium, zinc, or tin.
Gold is a precious metal indeed due to the less availability of gold as compared to the other metals but it is not the correct explanation for the auric chloride not being stored in containers made from the above-mentioned elements.
Hence, the correct option is B.

Note
Auric chloride or $ {\text{AuC}}{{\text{l}}_{\text{3}}} $ is highly soluble in water as well as in ethanol. It decomposes at temperature above $ {\text{160}}{{\text{ }}^{\text{o}}}{\text{C}} $ or in the presence of heat. It exists as a bridged dimer in both the solid as well as in the vapour phase at least at low temperatures.