Step 1: Understanding the Assertion (A):
The assertion states that a piece of Zinc metal gets a reddish-brown coating when kept in copper sulfate solution for some time. This is true. When zinc metal is placed in a copper sulfate (CuSO₄) solution, zinc displaces copper from the solution because zinc is more reactive than copper. The copper ions (Cu²⁺) are reduced to copper metal, which forms a reddish-brown coating on the surface of the zinc.
Step 2: Understanding the Reason (R):
The reason states that copper is a more reactive metal than zinc. This is false. In fact, zinc is more reactive than copper. Zinc can displace copper from its compounds, which is the basis of the reaction that produces the reddish-brown coating of copper on the zinc.
Step 3: Explanation of the Relationship Between Assertion and Reason:
- The assertion (A) is true: zinc gets a reddish-brown copper coating when placed in copper sulfate solution due to a displacement reaction.
- The reason (R) is false: copper is not more reactive than zinc; in fact, zinc is more reactive than copper.
Step 4: Conclusion:
The correct answer is: (A) is true, but (R) is false.