The vapour density of a volatile chloride of a metal is 95 and the specific heat of the metal is 0.13 cal/g. The equivalent mass of the metal will be approximately.

Options

A. 6 g
B. 12.3 g
C. 18 g
D. 24 g

Answer

To solve the problem of finding the equivalent mass of the metal from the given vapor density and specific heat, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Data:**
- Vapor Density (VD) of the volatile chloride = 95
- Specific Heat (SH) of the metal = 0.13 cal/g

2. **Calculate the Atomic Weight of the Metal:**
- We use the formula:
\[ \text{Atomic Weight} = \frac{6.4}{\text{Specific Heat}} \]
- Substituting the given specific heat:
\[ \text{Atomic Weight} = \frac{6.4}{0.13} \approx 49.23 \text{ g/mol} \]

3. **Calculate the Molecular Weight of the Metal Chloride:**
- The relationship between molecular weight (MW) and vapor density is given by:
\[ \text{Molecular Weight} = 2 \times \text{Vapor Density} \]
- Substituting the given vapor density:
\[ \text{Molecular Weight} = 2 \times 95 = 190 \text{ g/mol} \]

4. **Determine the Amount of Chlorine in the Metal Chloride:**
- The molecular weight of the metal chloride is the sum of the atomic weight of the metal and the weight of chlorine:
\[ \text{Weight of Chlorine} = \text{Molecular Weight} - \text{Atomic Weight} \]
- Substituting the values:
\[ \text{Weight of Chlorine} = 190 - 49.23 \approx 140.77 \text{ g} \]

5. **Calculate the Moles of Chlorine:**
- The molar mass of chlorine (Cl) is approximately 35.5 g/mol. Therefore, the number of moles of chlorine is:
\[ \text{Moles of Cl} = \frac{140.77}{35.5} \approx 4 \text{ moles} \]

6. **Determine the Valency of the Metal:**
- The valency of the metal is equal to the number of moles of chlorine, which is 4.

7. **Calculate the Equivalent Mass of the Metal:**
- The equivalent mass can be calculated using the formula:
\[ \text{Equivalent Mass} = \frac{\text{Atomic Mass}}{\text{Valency}} \]
- Substituting the values:
\[ \text{Equivalent Mass} = \frac{49.23}{4} \approx 12.3 \text{ g} \]

### Final Answer:
The equivalent mass of the metal is approximately **12.3 g**.