A mixture of naphthalene and oxalic acid can be separated by :

Options

A. chromatography
B. sublimation
C. fractional crystallisation
D. distillation.

Answer

To separate a mixture of naphthalene and oxalic acid, we can use the technique of sublimation. Here’s a step-by-step explanation of the process:

### Step-by-Step Solution:

1. **Understanding Sublimation**:
- Sublimation is the process where a solid turns directly into vapor without passing through the liquid phase. Naphthalene has a sublimation point of about 78°C.

2. **Heating the Mixture**:
- When the mixture of naphthalene and oxalic acid is heated to a temperature of 78°C, naphthalene will start to sublime, turning into vapor.

3. **Collecting the Vapors**:
- As naphthalene sublimates, it can be collected by cooling the vapor. This can be done using a cold surface or a condenser, where the vapor will turn back into solid naphthalene.

4. **Remaining Oxalic Acid**:
- After the sublimation process, oxalic acid will remain in the container as it does not sublime at this temperature. Thus, we will have separated naphthalene from oxalic acid.

5. **Final Separation**:
- The solid naphthalene can be collected from the cold surface, while oxalic acid remains in the original container, achieving a successful separation of the two substances.

### Conclusion:
The correct method to separate a mixture of naphthalene and oxalic acid is through sublimation.

---