Which of the following does not give oxygen on heating?

Options

A. `KClO_(3)`
B. ` Zn(ClO_(3))_(2)`
C. ` K_(2)Cr_(2)O_(7)`
D. `(NH_(4))_(2)Cr_(2)O_(7)`

Explanation

To determine which of the following compounds does not release oxygen upon heating, we will analyze each option provided:

1. **Potassium Chlorate (KClO3)**:
- When potassium chlorate is heated, it decomposes to form potassium chloride (KCl) and oxygen gas (O2).
- The reaction can be represented as:
\[ 2 KClO_3 \rightarrow 2 KCl + 3 O_2 \]
- Therefore, potassium chlorate does release oxygen upon heating.

2. **Zinc Chlorate (Zn(ClO3)2)**:
- Zinc chlorate also decomposes upon heating to produce zinc chloride (ZnCl2) and oxygen gas.
- The reaction can be represented as:
\[ 2 Zn(ClO_3)_2 \rightarrow 2 ZnCl_2 + 3 O_2 \]
- Hence, zinc chlorate releases oxygen when heated.

3. **Potassium Dichromate (K2Cr2O7)**:
- Potassium dichromate decomposes upon heating to produce potassium chromate (K2CrO4) and oxygen gas.
- The reaction can be represented as:
\[ 2 K_2Cr_2O_7 \rightarrow 2 K_2CrO_4 + O_2 \]
- Therefore, potassium dichromate also releases oxygen upon heating.

4. **Ammonium Dichromate ((NH4)2Cr2O7)**:
- When ammonium dichromate is heated, it decomposes to form chromium(III) oxide (Cr2O3), water (H2O), and nitrogen gas (N2).
- The reaction can be represented as:
\[ (NH_4)_2Cr_2O_7 \rightarrow Cr_2O_3 + 4 H_2O + N_2 \]
- Notably, this reaction does not produce oxygen gas; instead, it produces nitrogen gas.

Based on the analysis above, the compound that does not give oxygen on heating is **Ammonium Dichromate ((NH4)2Cr2O7)**.

### Final Answer:
**Ammonium Dichromate ((NH4)2Cr2O7)** does not give oxygen on heating.