Question

The mass of 56 mL of a gas at STP is found to be 0.25 g. What is its molecular mass?​

Answer 1

Answer:

Volume at STP is given = 56ml = 56 × 10^-3 l

moles at stp = Volume in litre/( 22.4 mol per litre)

Moles of gas = 56×10^-3/22.4 =25 × 10^-4 moles

Weight of gas = 0.25g

Molecular mass= weight/moles

Molecular mass of gas = 0.25/( 25×10^-4)

= 100g.