A mixture of two liquids A and B having boiling points of A is `70^@C` and boiling point of B is `100^@C` distills at `101.2^@C` as single liquid, hence this mixture is

Options

A. Ideal solution
B. Non ideal solution showing +ve deviation
C. Non ideal solution showing -ve deviation
D. Immiscible solution

Answer

To solve the problem, we need to analyze the boiling points of the two liquids A and B, and their behavior when mixed together.

### Step 1: Identify the boiling points of the liquids
- Liquid A has a boiling point of 70°C.
- Liquid B has a boiling point of 100°C.

**Hint:** Remember that the boiling point of a liquid is the temperature at which its vapor pressure equals the atmospheric pressure.

### Step 2: Determine the boiling point of the mixture
- The mixture of liquids A and B distills at 101.2°C.

**Hint:** The boiling point of a mixture can provide insight into the interactions between the components of the mixture.

### Step 3: Compare the boiling point of the mixture to the boiling points of the individual components
- The boiling point of the mixture (101.2°C) is higher than the boiling point of liquid B (100°C), which is the higher boiling point of the two components.

**Hint:** A higher boiling point than the component with the highest boiling point suggests that the mixture has different interactions than the pure components.

### Step 4: Analyze the implications of the boiling point
- If the boiling point of the mixture is higher than that of the pure components, it indicates that the intermolecular forces between the molecules of A and B are stronger than the forces between the molecules of A and A or B and B.

**Hint:** Stronger interactions in the mixture suggest that the solution is not ideal and may exhibit a deviation from Raoult's law.

### Step 5: Determine the type of deviation
- Since the boiling point of the mixture is higher than expected, it suggests that the solution exhibits a positive deviation from Raoult's law. However, the context of the problem indicates that the interactions between A and B are stronger than those between A and A or B and B, which indicates a negative deviation.

**Hint:** Non-ideal solutions can show either positive or negative deviations based on the strength of interactions between different molecules compared to the same type of molecules.

### Conclusion
Based on the analysis, the mixture of liquids A and B distills at a boiling point of 101.2°C, which indicates that it is a non-ideal solution showing a negative deviation.

**Final Answer:** The mixture is a non-ideal solution showing a negative deviation (Option C).