When an ant stings a person, the solution of substance A is rubbed on the stung area of the skin to get relief from pain. The substance A is also used in kitchen for cooking purposes. Another susbtance B is sour in taste and contains an organic acid C. It is used in making pickles. When a solution of A is mixed with B, then a change D takes place to produce bubbles of gas E.
Name the gas E.

Answer

To solve the question step by step, we will analyze the information provided and identify the substances involved, their properties, and the resulting gas produced from their reaction.

### Step-by-Step Solution:

1. **Identify Substance A**:
- The question states that when an ant stings a person, a solution of substance A is used for relief. It is also mentioned that substance A is used in cooking.
- Ant stings are acidic in nature, so to neutralize the sting, a basic substance is needed. A common basic substance used in cooking is **baking soda** (sodium bicarbonate, NaHCO₃).
- Therefore, **Substance A = Baking Soda (NaHCO₃)**.

2. **Identify Substance B**:
- The question describes substance B as sour in taste and containing an organic acid, which is used in making pickles.
- A common sour substance used in cooking and pickling is **vinegar**, which contains **acetic acid (CH₃COOH)**.
- Therefore, **Substance B = Vinegar (which contains Acetic Acid)**.

3. **Identify the Organic Acid C**:
- From the previous step, we established that the organic acid C present in vinegar is **acetic acid (CH₃COOH)**.

4. **Determine the Reaction**:
- When a solution of A (baking soda) is mixed with B (vinegar), a chemical reaction occurs.
- The reaction can be written as:
\[ \text{NaHCO}_3 + \text{CH}_3\text{COOH} \rightarrow \text{CH}_3\text{COONa} + \text{H}_2\text{O} + \text{CO}_2 \]
- This reaction produces sodium acetate, water, and carbon dioxide.

5. **Identify the Gas E**:
- The question asks for the gas E produced during the reaction. From the balanced equation, we see that **carbon dioxide (CO₂)** is produced as a gas.
- Therefore, **Gas E = Carbon Dioxide (CO₂)**.

### Final Answer:
The gas E produced when a solution of substance A (baking soda) is mixed with substance B (vinegar) is **Carbon Dioxide (CO₂)**.

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