Question

The increasing order of acidity of the given molecules in aqueous media is 

• A. IV < I < II < III
• B. II < I < IV < III
• C. II < IV < I < III
• D. IV < II < I < III

Hint:

Electron-withdrawing groups like fluorine in fluoroacetic acid increase the acidity by stabilizing the negative charge on the conjugate base.

Answer 1

The Correct Option is C

Step 1: Understanding acidity.
The acidity of compounds depends on the ability to donate a proton (H$^+$). In aqueous media, electron-withdrawing groups increase acidity, while electron-donating groups decrease acidity. The presence of an electronegative substituent like F in fluoroacetic acid makes it more acidic than acetic acid or phenol. Alcohols, like methanol (CH$_3$OH), are the least acidic.
Step 2: Conclusion.
The increasing order of acidity is CH$_3$OH (IV) > acetic acid (II) > phenol (I) > fluoroacetic acid (III), corresponding to option (D).