A substance 'X' having low melting point, does not conduct electricity in both solid and liquid state. 'X' can be :

Options

A. Hg
B. ZnS
C. SiC
D. ` C Cl_4 `

Explanation

To determine the substance 'X' that has a low melting point and does not conduct electricity in both solid and liquid states, we will analyze the given options step by step.

### Step 1: Analyze the properties of 'X'
- **Low melting point**: This suggests that 'X' is likely to be a molecular compound or a non-metallic solid.
- **Does not conduct electricity in solid and liquid states**: This indicates that 'X' is likely to be a non-conductive substance, which means it does not have free-moving charged particles (like ions or electrons).

### Step 2: Evaluate Option A: Mercury (Hg)
- Mercury is a metal that exists in a liquid state at room temperature.
- Metals are good conductors of electricity due to the presence of free electrons.
- **Conclusion**: Mercury does not satisfy the conditions of 'X' because it conducts electricity.

### Step 3: Evaluate Option B: Zinc Sulfide (ZnS)
- ZnS is an ionic compound and typically has a high melting point.
- Although it can conduct electricity in certain conditions (as a semiconductor), it is not a good conductor in its solid state.
- **Conclusion**: ZnS does not satisfy the conditions of 'X' because it can conduct electricity under specific conditions and has a high melting point.

### Step 4: Evaluate Option C: Silicon Carbide (SiC)
- Silicon carbide is a covalent compound and is also known to be a semiconductor.
- It has a high melting point and can conduct electricity in certain conditions.
- **Conclusion**: Silicon carbide does not satisfy the conditions of 'X' because it conducts electricity and has a high melting point.

### Step 5: Evaluate Option D: Carbon Tetrachloride (CCl4)
- CCl4 is a molecular compound with a tetrahedral structure.
- It is non-polar, which means it has no dipole moment and does not conduct electricity in either solid or liquid states.
- CCl4 has a low melting point of approximately -22 degrees Celsius.
- **Conclusion**: CCl4 satisfies all the conditions of 'X' as it has a low melting point and does not conduct electricity in both solid and liquid states.

### Final Answer
The substance 'X' can be **Carbon Tetrachloride (CCl4)**.

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