In the following reaction, ZnO is respectively acting as a/an
(i) `ZnO+Na_(2)O rarr Na_(2)ZnO_(2)`
(ii) `ZnO+CO_(2)rarr ZnCO_(3)`

Options

A. (a) acid and acid
B. (b) base and acid
C. (c) base and base
D. (d) acid and base

Answer

To solve the question regarding the behavior of ZnO in the given reactions, we will analyze each reaction step by step.

### Step 1: Analyze the first reaction
The first reaction is:
\[ \text{ZnO} + \text{Na}_2\text{O} \rightarrow \text{Na}_2\text{ZnO}_2 \]

- Here, ZnO is reacting with Na2O, which is a basic oxide (sodium oxide).
- In this reaction, ZnO is acting as an acid because it reacts with a base (Na2O) to form a salt (Na2ZnO2).

### Step 2: Analyze the second reaction
The second reaction is:
\[ \text{ZnO} + \text{CO}_2 \rightarrow \text{ZnCO}_3 \]

- In this reaction, ZnO is reacting with CO2, which is an acidic oxide (carbon dioxide).
- Here, ZnO acts as a base because it reacts with an acid (CO2) to form another salt (ZnCO3).

### Step 3: Conclusion about ZnO
Based on the analysis of both reactions:
- In the first reaction, ZnO acts as an acid.
- In the second reaction, ZnO acts as a base.

This behavior indicates that ZnO is an **amphoteric oxide**, meaning it can act as both an acid and a base depending on the reacting species.

### Final Answer
- In the first reaction, ZnO is acting as an **acid**.
- In the second reaction, ZnO is acting as a **base**.