Azeotropic mixture of water (B.P. = 100°C) and nitric acid (B P = 83°C) boils at 393.5 K During fractional distillation of mixture, it is possible to obtain

Options

A. Neither `HNO_3` nor `H_2O`
B. Pure`HNO_3`
C. Pure `H_2O`
D. Both HNO3 and H2O in pure state

Answer

To solve the problem regarding the azeotropic mixture of water and nitric acid, we need to understand the concept of azeotropes and how they behave during fractional distillation. Here’s a step-by-step solution:

### Step 1: Understand Azeotropic Mixtures
An azeotropic mixture is a mixture of two or more liquids that has a constant boiling point and composition throughout the distillation process. This means that when the mixture boils, it produces vapor that has the same composition as the liquid mixture.

**Hint:** Remember that azeotropes do not change composition when they boil.

### Step 2: Identify the Boiling Points
In this case, we have:
- Boiling point of water (H₂O) = 100°C (373 K)
- Boiling point of nitric acid (HNO₃) = 83°C (356 K)
- The azeotropic mixture boils at 393.5 K (approximately 120.5°C).

**Hint:** Compare the boiling points of the individual components with the boiling point of the azeotropic mixture.

### Step 3: Analyze the Boiling Point of the Azeotropic Mixture
The boiling point of the azeotropic mixture (393.5 K) is higher than the boiling points of both components. This indicates that the mixture has a unique composition that prevents the separation of its components through simple distillation.

**Hint:** Azeotropic mixtures often have boiling points that do not correspond to the boiling points of the individual components.

### Step 4: Determine the Separation Possibility
Since the azeotropic mixture has a constant composition, when it is distilled, the vapor produced will have the same composition as the liquid. Therefore, it is not possible to separate pure HNO₃ or pure H₂O from the azeotropic mixture.

**Hint:** If the composition remains constant in both liquid and vapor phases, separation is not achievable.

### Step 5: Conclusion
Based on the behavior of azeotropic mixtures, during fractional distillation of the given mixture, it is not possible to obtain either pure HNO₃ or pure H₂O. The correct answer is that neither HNO₃ nor H₂O can be obtained in pure form.

**Final Answer:** Neither HNO₃ nor H₂O can be obtained.