Sodium salts of some acids are very useful as food preservatives. Suggest a few such acids ?

Explanation

### Step-by-Step Solution:

1. **Understanding Food Preservatives**:
- Food preservatives are substances added to food to prevent spoilage caused by microbial growth, oxidation, or other chemical reactions. They can be naturally occurring or synthetically produced.

2. **Identifying Sodium Salts of Acids**:
- Sodium salts of certain acids are effective as preservatives. These salts help to inhibit the growth of bacteria, molds, and yeasts, thereby extending the shelf life of food products.

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