In liquid states, substances X and Y are miscible with each other. If melting point and boiling point of X are `-90^@C` and `70^@C` respectively and that of Y are `-88^@C` and `107^@C` respectively then, which of the following statements is correct regarding their separation?

Options

A. At room temperature, X and Y both are volatile liquids hence, can be separated by fractional distillation.
B. At room temperature, X is a solid while Y is a volatile liquid hence, can be separated by evaporation.
C. At room temperature, X is a solid and Y is a liquid hence, can be separated by filtration.
D. At room temperature, X and Y both are liquids hence, can be separated by simple distillation.

Answer

To solve the problem regarding the separation of substances X and Y, we need to analyze their physical properties and determine the best method for their separation based on those properties.

### Step-by-Step Solution:

1. **Identify the Properties of X and Y:**
- Substance X:
- Melting Point: -90°C
- Boiling Point: 70°C
- Substance Y:
- Melting Point: -88°C
- Boiling Point: 107°C

2. **Determine the State of X and Y at Room Temperature:**
- Room temperature is typically around 25°C.
- Since both substances have boiling points above room temperature, they will be in liquid form at room temperature.

3. **Analyze the Melting Points:**
- The melting point of X (-90°C) is lower than that of Y (-88°C). This means that at room temperature, both substances are indeed liquids.

4. **Analyze the Boiling Points:**
- The boiling point of X (70°C) is lower than that of Y (107°C). This indicates that X is more volatile than Y.

5. **Determine the Separation Method:**
- Since both substances are miscible and are in liquid form at room temperature, we need to consider the boiling points for separation.
- The difference in boiling points is 107°C - 70°C = 37°C, which is greater than 25°C.
- This significant difference in boiling points suggests that simple distillation can be used effectively to separate the two liquids.

6. **Conclusion:**
- The correct statement regarding the separation of substances X and Y is that they can be separated by simple distillation due to the significant difference in their boiling points.

### Final Answer:
The correct statement regarding their separation is that they can be separated by simple distillation.

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