Which of the following is not an organic acid?

Options

A. tartaric acid
B. oxalic acid
C. ascorbic acid
D. nitric acid

Explanation

To determine which of the following acids is not an organic acid, we need to identify the nature of each acid provided in the options. Organic acids contain carbon, while inorganic acids do not.

### Step-by-Step Solution:

1. **Identify the Categories of Acids**:
- Organic acids contain carbon and typically have a carboxyl group (-COOH).
- Inorganic acids do not contain carbon.

2. **Analyze Each Acid**:
- **Tartaric Acid**:
- Tartaric acid has the chemical structure that includes carbon and a carboxyl group. It is found in grapes and is classified as an organic acid.
- **Oxalic Acid**:
- Oxalic acid also contains carbon and has two carboxyl groups. It is found in various fruits and vegetables, making it an organic acid.
- **Ascorbic Acid**:
- Ascorbic acid (Vitamin C) contains carbon and is found in citrus fruits. It is classified as an organic acid.
- **Nitric Acid**:
- Nitric acid has the chemical formula HNO3. It does not contain carbon, which classifies it as an inorganic acid.

3. **Conclusion**:
- Among the given options, **Nitric Acid (Option D)** is the only acid that is not an organic acid. Therefore, the answer to the question is **Nitric Acid**.

### Final Answer:
**Nitric Acid is not an organic acid.**

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