The compound insoluble in acetic acid is

Options

A. Calcium oxide
B. Calcium carbonate
C. Calcium oxalate
D. Calcium hydroxide

Explanation

To determine which compound is insoluble in acetic acid among the given options (calcium oxide, calcium carbonate, calcium oxalate, and calcium hydroxide), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Nature of Acetic Acid**:
- Acetic acid (CH₃COOH) is a weak acid. It can dissolve certain compounds, especially those that can react with acids.

2. **Identify the Compounds**:
- The compounds in question are:
- Calcium oxide (CaO)
- Calcium carbonate (CaCO₃)
- Calcium oxalate (CaC₂O₄)
- Calcium hydroxide (Ca(OH)₂)

3. **Analyze Each Compound**:
- **Calcium Oxide (CaO)**:
- This is a strong base and reacts with acetic acid to form calcium acetate, making it soluble.
- **Calcium Carbonate (CaCO₃)**:
- This compound reacts with acetic acid to produce carbon dioxide gas and calcium acetate, indicating it is soluble in acetic acid.
- **Calcium Hydroxide (Ca(OH)₂)**:
- This is also a strong base and will react with acetic acid, resulting in calcium acetate and water, thus it is soluble.
- **Calcium Oxalate (CaC₂O₄)**:
- This is a weak base and does not react significantly with acetic acid, making it insoluble in acetic acid.

4. **Conclusion**:
- Among the options, calcium oxalate is the compound that is insoluble in acetic acid.

### Final Answer:
The compound that is insoluble in acetic acid is **calcium oxalate (CaC₂O₄)**.

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