Vapour density of a gas is 22. What is its molecular mass ?

Options

A. 23
B. 22
C. 44
D. 11

Explanation

To find the molecular mass of a gas given its vapor density, we can use the relationship between vapor density and molecular mass. Here’s the step-by-step solution:

### Step 1: Understand the relationship between vapor density and molecular mass
Vapor density (VD) is defined as the mass of a certain volume of the gas compared to the mass of the same volume of hydrogen gas. The formula relating vapor density to molecular mass (M) is:
\[ \text{Vapor Density} = \frac{\text{Molecular Mass}}{2} \]

### Step 2: Rearrange the formula to find molecular mass
To find the molecular mass from the vapor density, we can rearrange the formula:
\[ \text{Molecular Mass} = 2 \times \text{Vapor Density} \]

### Step 3: Substitute the given vapor density into the equation
We are given that the vapor density of the gas is 22. Now, we can substitute this value into the equation:
\[ \text{Molecular Mass} = 2 \times 22 \]

### Step 4: Calculate the molecular mass
Now, perform the multiplication:
\[ \text{Molecular Mass} = 44 \]

### Final Answer
The molecular mass of the gas is **44 g/mol**.

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