Which of the following give `O_(2)` on strong heating ?

Options

A. `KMnO_(4)`
B. `K_(2)Cr_(2)O_(7)`
C. `AgNO_(3)`
D. `ZnO`

Explanation

To determine which compounds give \( O_2 \) on strong heating, we will analyze the behavior of each compound when subjected to heat.

### Step-by-Step Solution:

1. **Identify the Compounds**: First, we need to identify the compounds listed in the question. Let's assume they are:
- A: \( KMnO_4 \) (Potassium permanganate)
- B: \( K_2Cr_2O_7 \) (Potassium dichromate)
- C: \( 2ZnO \) (Zinc oxide)
- D: \( HNO_3 \) (Nitric acid)

2. **Analyze the Decomposition of Each Compound**:
- **For \( KMnO_4 \)**: When heated, potassium permanganate decomposes to form potassium manganate, potassium oxide, and releases oxygen gas:
\[ 2KMnO_4 \rightarrow K_2MnO_4 + MnO_2 + O_2 \]
- **For \( K_2Cr_2O_7 \)**: Potassium dichromate decomposes upon heating to yield potassium chromate, chromium(III) oxide, and oxygen gas:
\[ 2K_2Cr_2O_7 \rightarrow 2K_2CrO_4 + Cr_2O_3 + O_2 \]
- **For \( ZnO \)**: Zinc oxide does not release oxygen upon heating; it is stable and does not decompose to release \( O_2 \).
- **For \( HNO_3 \)**: Concentrated nitric acid decomposes upon heating to produce nitrogen dioxide, water, and oxygen:
\[ 4HNO_3 \rightarrow 4NO_2 + 2H_2O + O_2 \]

3. **Conclusion**: From the analysis, we find that:
- \( KMnO_4 \) and \( K_2Cr_2O_7 \) and \( HNO_3 \) release \( O_2 \) when heated.
- \( ZnO \) does not release \( O_2 \) upon heating.

Thus, the compounds that give \( O_2 \) on strong heating are \( KMnO_4 \), \( K_2Cr_2O_7 \), and \( HNO_3 \).

### Final Answer:
The compounds that give \( O_2 \) on strong heating are \( KMnO_4 \), \( K_2Cr_2O_7 \), and \( HNO_3 \).

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