Which of the following binary solutions form azeotropic mixture ?
I. `H_(2)O + C_(2)H_(5)OH` II Benzene + Toluene
III. `H_(2)O + HNO_(3)` IV Phenol+ Aniline

Options

A. I and IV only
B. I, II and III only
C. III and IV only
D. I, III and IV only

Explanation

To determine which of the given binary solutions form azeotropic mixtures, we need to analyze each option based on the properties of ideal and non-ideal solutions.

### Step-by-Step Solution:

1. **Understanding Azeotropic Mixtures**:
- Azeotropic mixtures are solutions that have the same composition in both liquid and vapor phases. They do not obey Raoult's law and are typically formed by non-ideal solutions.

2. **Analyzing Each Option**:
- **I. `H2O + C2H5OH` (Water + Ethanol)**:
- This is a non-ideal solution. Water and ethanol form an azeotropic mixture, which means they will exhibit the same composition in both liquid and vapor phases.

- **II. Benzene + Toluene**:
- This is an ideal solution. Benzene and toluene obey Raoult's law and do not form an azeotropic mixture.

- **III. `H2O + HNO3` (Water + Nitric Acid)**:
- This is a non-ideal solution. Water and nitric acid also form an azeotropic mixture due to strong interactions between the components.

- **IV. Phenol + Aniline**:
- This is a non-ideal solution. Phenol and aniline do not obey Raoult's law and can form an azeotropic mixture.

3. **Conclusion**:
- Based on the analysis, the solutions that form azeotropic mixtures are:
- I. `H2O + C2H5OH`
- III. `H2O + HNO3`
- IV. Phenol + Aniline

Thus, the correct options that form azeotropic mixtures are I, III, and IV.

### Final Answer:
The binary solutions that form azeotropic mixtures are:
- I. `H2O + C2H5OH`
- III. `H2O + HNO3`
- IV. Phenol + Aniline