Choose the correct order of acidity:

Options

A. p-nitrophenol `gt `p-cresol `gt` phenol `gt` p-chlorophenol
B. p-nitrophenol `lt` p-cresol `lt` phenol `lt` p-chlorophenol
C. phenol `gt` p-cresol `gt` p-nitrophenol `gt` p-chlorophenol
D. phenol `gt` p-chlorophenol `gt` p-nitrophenol `gt` p-cresol

Explanation

To determine the correct order of acidity among perinitrophenol, phenol, peracrysol, and peraclorophenol, we can follow these steps:

### Step 1: Understand the Structures
1. **Perinitrophenol**: Contains a nitro group (-NO2) at the para position relative to the hydroxyl group (-OH).
2. **Phenol**: Contains a hydroxyl group (-OH) directly attached to a benzene ring.
3. **Peracrysol**: Contains a methyl group (-CH3) at the para position relative to the hydroxyl group.
4. **Peraclorophenol**: Contains a chloro group (-Cl) at the para position relative to the hydroxyl group.

### Step 2: Analyze Electron-Withdrawing and Electron-Donating Effects
- **Electron-Withdrawing Groups (EWGs)**: These groups, such as -NO2 and -Cl, pull electron density away from the benzene ring and the hydroxyl group, making the O-H bond weaker and thus increasing acidity.
- **Electron-Donating Groups (EDGs)**: Groups like -CH3 donate electron density to the ring, strengthening the O-H bond and decreasing acidity.

### Step 3: Determine Acidity Based on Substituents
1. **Perinitrophenol**: The nitro group is a strong electron-withdrawing group, which significantly increases the acidity by weakening the O-H bond.
2. **Peraclorophenol**: The chloro group is also an electron-withdrawing group, but it is less effective than the nitro group, making this compound less acidic than perinitrophenol but more acidic than phenol.
3. **Phenol**: Lacks any strong electron-withdrawing or donating groups, making it moderately acidic.
4. **Peracrysol**: The methyl group is an electron-donating group, which increases the electron density around the O-H bond, making it the least acidic among these compounds.

### Step 4: Establish the Order of Acidity
Based on the analysis:
- **Most Acidic**: Perinitrophenol (due to the strong electron-withdrawing effect of the nitro group)
- **Next**: Peraclorophenol (due to the electron-withdrawing effect of the chloro group)
- **Then**: Phenol (neutral, no strong effects)
- **Least Acidic**: Peracrysol (due to the electron-donating effect of the methyl group)

### Final Order of Acidity
The correct order of acidity is:
**Perinitrophenol > Peraclorophenol > Phenol > Peracrysol**