Certain metals have the capacity to displace some metals from their salt solutions. These reactions are known as metal displacement reactions. A metal placed higher in activity series can displace the metal occupying lower position from aqueous solution of its salt or a more reactive metal can displace less reactive metal from its salt solution.
Q. If a zinc rod is dipped in copper sulphate solution, following changes will be noticed. mark the correct observations.
(i) Zinc rod slowly loses its weight.
(ii) Copper settles at the bottom of the beaker.
(iii) Blue colour of copper sulphate disappears.

Options

A. (i) and (ii) only
B. (i), (ii) and (iii) only
C. (i) and (iii) only
D. (iii) only

Explanation

To solve the question regarding the observations made when a zinc rod is dipped in copper sulfate solution, we can analyze the situation step by step.

### Step-by-step Solution:

1. **Understanding the Reaction**:
- When a zinc rod is placed in a copper sulfate solution, a chemical reaction occurs because zinc is more reactive than copper according to the activity series of metals.

2. **Displacement Reaction**:
- The more reactive zinc displaces the less reactive copper from its salt solution. The reaction can be represented as:
\[ \text{Zn (s)} + \text{CuSO}_4 \text{(aq)} \rightarrow \text{ZnSO}_4 \text{(aq)} + \text{Cu (s)} \]

3. **Observation of Weight Loss**:
- As the zinc rod reacts with the copper sulfate solution, zinc ions enter the solution, and the solid zinc rod starts to dissolve. This means that the zinc rod will lose weight over time.
- **Observation (i)**: Zinc rod slowly loses its weight. **(True)**

4. **Formation of Copper**:
- During the reaction, copper ions in the solution are displaced and will deposit as solid copper on the bottom of the beaker.
- **Observation (ii)**: Copper settles at the bottom of the beaker. **(True)**

5. **Change in Color of the Solution**:
- The initial blue color of the copper sulfate solution is due to the presence of copper ions. As copper ions are displaced and solid copper is formed, the blue color of the solution will fade and eventually disappear.
- **Observation (iii)**: Blue color of copper sulfate disappears. **(True)**

### Conclusion:
All three observations are correct:
- (i) Zinc rod slowly loses its weight. **(True)**
- (ii) Copper settles at the bottom of the beaker. **(True)**
- (iii) Blue color of copper sulfate disappears. **(True)**

Thus, the correct answer is that all observations are true.