Question

The mass of gas 94.5ml of a gas at STP is found 0.2231g. Calculate molecular mass

Answer 1

Answer:

At STP mass of 94.5 ml of gas=0.2231g

∴ molecular mass of 22400 ml of gas =0.223194.5×22400=52.9g

Explanation:

Answer 2

Answer: The molecular mass of given gas is 52.87 g/mol.

Explanation:

We are given:

Volume of gas = 94.5 mL = 0.0945 L    (Conversion factor:  1 L = 1000 mL)

Mass of gas = 0.2231 g

At STP:

22.4 L of volume is occupied by 1 mole of gas.

So, 0.0945 L of volume will be occupied by = $\frac{1mol}{22.4L}\times 0.0945L=0.00422mol$ of gas.

To calculate the molecular mass of solute, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of gas = 0.00422 mol

Given mass of gas = 0.2231 g

Putting values in above equation, we get:

$0.00422mol=\frac{0.2231g}{\text{Molar mass of gas}}\\\\\text{Molar mass of gas}=52.87g/mol$

Hence, the molecular mass of given gas is 52.87 g/mol.