Question

The mass of 94.5 ml of a gas at STP is found to be 0.2231 gm.calculate its molecular mass.

Answer 1

Given:-

→ Volume of the gas = 94.5 mL

→ Mass of the given volume of gas at

STP = 0.2231 g

To find:-

→ Molecular mass of the gas

Solution:-

We know that:-

∵ 22.4L at STP = 1 mole

∴ 22400mL of a gas at STP = 1 mole

Hence, number of moles in 94.5mL of the gas at STP :-

=> 94.5/22400

=> 0.00421875 mole

Now, we know :-

Molecular mass of a gas :-

= Given mass of gas/No of moles of gas

= 0.2231/0.00421875

= 52.9 g/mol

Thus, molecular mass of the gas

is 52.9g/mol .