Which of the following options are correct for the reaction $2[\mathrm{Au}(\mathrm{CN})_{2}]^{-}_{(\mathrm{aq})}+\mathrm{Zn}(\mathrm{s}) \rightarrow 2 \mathrm{Au}(\mathrm{s})+[\mathrm{Zn}(\mathrm{CN})_{4}]^{2-}_{(\mathrm{aq})}$ A. Redox reaction B. Displacement reaction C. Decomposition reaction D. Combination reaction Choose the correct answer from the options given below:

JEE Main · 2023 · 06 Apr 2023 · Shift 1 · Redox Reactions and Electrochemistry

Which of the following options are correct for the reaction

2 [Au (CN)_{2}]_{(aq)}^{-} + Zn (s) \to 2 Au (s) + [Zn (CN)_{4}]_{(aq)}^{2 -}

A. Redox reaction
B. Displacement reaction
C. Decomposition reaction
D. Combination reaction

Choose the correct answer from the options given below:

(A)A and B only✓ Correct
(B)A only
(C)C and D only
(D)A and D only

Answer: (A)

Solution

Gold is reduced from the

+ 1

state in

[Au (CN)_{2}]^{-}

to metallic

Au

, while zinc is oxidised from

0

+ 2

, so electron transfer occurs and the change is a redox reaction. Because the more reactive zinc drives gold out of its complex, it is also a displacement reaction. It is neither a combination nor a decomposition. Hence the reaction is both redox and displacement.

JEE Main · 2023 · 06 Apr 2023 · Shift 1 · Single correct option

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JEE Main · 2023 · 06 Apr 2023 · Shift 1 · Redox Reactions and Electrochemistry

Solution

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