Chemical volcano is produced on heating

Options

A. `K_(2)Cr_(2)O_(7)`
B. `(NH_(4))_(2)Cr_(2)O_(7)`
C. `ZnCr_(2)O_(7)`
D. `K_(2)CrO_(4)`

Explanation

To determine which compound produces a chemical volcano upon heating, we will analyze the options provided: K2Cr2O7, NH4)2Cr2O7, ZnCr2O7, and K2CrO4.

### Step-by-Step Solution:

1. **Understanding the Concept of Chemical Volcano:**
- A chemical volcano is a phenomenon observed during the heating of certain compounds, where gas is released and solid products are expelled, resembling a volcanic eruption.

2. **Analyzing Each Compound:**
- **K2Cr2O7 (Potassium Dichromate):**
- When heated, potassium dichromate decomposes but does not produce a significant gas release or the visual effect of a volcano.
- **NH4)2Cr2O7 (Ammonium Dichromate):**
- Upon heating, ammonium dichromate decomposes to produce nitrogen gas (N2) and chromic oxide (Cr2O3). The rapid release of gas and the formation of solid Cr2O3 creates the appearance of a volcanic eruption.
- **ZnCr2O7 (Zinc Chromate):**
- Heating zinc chromate does not lead to the formation of a gas or the volcanic effect.
- **K2CrO4 (Potassium Chromate):**
- Similar to potassium dichromate, potassium chromate does not produce a significant gas release or volcanic appearance upon heating.

3. **Conclusion:**
- The only compound that produces a chemical volcano effect upon heating is **NH4)2Cr2O7 (Ammonium Dichromate)**, as it releases nitrogen gas and forms chromic oxide, creating a visual effect similar to a volcanic eruption.

### Final Answer:
The correct answer is **NH4)2Cr2O7 (Ammonium Dichromate)**.

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