Chemistry · REDOX REACTIONS

Given below are statements regarding competitive electron transfer reactions: (A) When a metallic zinc strip is placed in copper nitrate solution, equilibrium greatly favours the formation of products. (B) The presence of unreacted \( \text{Cu}^{2+} \) can be detected with high sensitivity by passing \( \text{H}_2\text{S} \) gas to form black \( \text{CuS} \). (C) In the reaction between metallic cobalt and nickel sulphate solution, the equilibrium greatly favours the products over the reactants. (D) The tendency of metals to release electrons follows the order: \( \text{Zn} > \text{Cu} > \text{Ag} \). Which of the above statements are correct?

1. A
   (A), (B), (C) and (D)
2. B
   (A) and (C) only
3. C
   (B), (C) and (D) only
4. D
   (A), (B) and (D) only