Assertion : Fluoroacetic acid is stronger acid than chloroacetic acid.
Reason : due to greater electron donating effect of F than Cl.

Answer

To solve the question regarding the assertion and reason about fluoroacetic acid and chloroacetic acid, we will analyze both statements step by step.

### Step 1: Understanding the Assertion
The assertion states that fluoroacetic acid is a stronger acid than chloroacetic acid. This is based on the stability of the conjugate base formed when each acid donates a proton (H⁺).

### Step 2: Analyzing the Conjugate Bases
When fluoroacetic acid (FCH₂COOH) donates a proton, it forms the conjugate base FCH₂COO⁻. Similarly, when chloroacetic acid (ClCH₂COOH) donates a proton, it forms the conjugate base ClCH₂COO⁻.

### Step 3: Stability of Conjugate Bases
The strength of an acid is determined by the stability of its conjugate base. The more stable the conjugate base, the stronger the acid.

- **Fluoroacetic Acid**: The conjugate base FCH₂COO⁻ has a fluorine atom, which is highly electronegative. This electronegativity pulls electron density away from the carboxylate group (COO⁻), stabilizing the negative charge.

- **Chloroacetic Acid**: The conjugate base ClCH₂COO⁻ has a chlorine atom, which is less electronegative than fluorine. Therefore, it does not stabilize the negative charge as effectively as fluorine does.

### Step 4: Conclusion on Assertion
Since the conjugate base of fluoroacetic acid is more stable than that of chloroacetic acid, fluoroacetic acid is indeed a stronger acid than chloroacetic acid. Thus, the assertion is **true**.

### Step 5: Understanding the Reason
The reason states that fluoroacetic acid is stronger due to the greater electron donating effect of F than Cl.

### Step 6: Analyzing the Reason
This statement is incorrect. Fluorine is actually an electron-withdrawing group due to its high electronegativity, which contributes to the stabilization of the negative charge in the conjugate base. Chlorine, while also an electron-withdrawing group, is not as effective as fluorine.

### Step 7: Conclusion on Reason
The reason provided is **false** because it incorrectly describes the nature of the influence of fluorine and chlorine on the stability of the conjugate base.

### Final Conclusion
- **Assertion**: True
- **Reason**: False

Therefore, the correct answer is that the assertion is true, but the reason is false.

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