Assertion: In 0.1 M HCl , `[H^+]` is also equal to 0.1 M but in 0.1 M `CH_3COOH, [H^+]` is not equal to 01 M.
Reason: HCl is completely ionized but `CH_3COOH` does not ionize completely.

Options

A. Assertion and reason both are correct statements and Reason is correct explanation for assertion.
B. Assertion and reason both are correct statement but reason is not correct explanation for assertion
C. Assertion is correct statement but reason is wrong statement.
D. Assertion is wrong statement but reason is correct statement

Answer

To solve the given assertion and reason question, we will analyze the statements step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that in a 0.1 M HCl solution, the concentration of hydrogen ions \([H^+]\) is equal to 0.1 M. In contrast, in a 0.1 M acetic acid (\(CH_3COOH\)) solution, the concentration of \([H^+]\) is not equal to 0.1 M.

2. **Analyzing HCl**:
- HCl is a strong acid. Strong acids completely dissociate in water. This means that if you have 0.1 M HCl, it will dissociate completely into hydrogen ions and chloride ions:
\[ HCl \rightarrow H^+ + Cl^- \]
- Therefore, for every mole of HCl, you get one mole of \(H^+\). Hence, in a 0.1 M HCl solution, \([H^+] = 0.1 \, M\).

3. **Analyzing Acetic Acid (\(CH_3COOH\))**:
- Acetic acid is a weak acid. Weak acids do not completely dissociate in water. The dissociation of acetic acid can be represented as:
\[ CH_3COOH \rightleftharpoons H^+ + CH_3COO^- \]
- The double arrow indicates that the dissociation is reversible and does not go to completion. Therefore, not all of the acetic acid will dissociate into \(H^+\) ions.

4. **Concentration of \([H^+]\) in Acetic Acid**:
- In a 0.1 M solution of acetic acid, only a fraction of it will dissociate into \(H^+\) ions. The actual concentration of \([H^+]\) will be less than 0.1 M because only a small portion of the acetic acid molecules ionize.

5. **Conclusion**:
- The assertion is correct because \([H^+]\) in 0.1 M HCl is indeed 0.1 M, while in 0.1 M \(CH_3COOH\), \([H^+]\) is less than 0.1 M.
- The reason is also correct as it explains that HCl is a strong acid that completely ionizes, while \(CH_3COOH\) is a weak acid that does not ionize completely.

### Final Statement:
Both the assertion and the reason are correct, and the reason correctly explains the assertion.

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