Question

The weight of 350 ml of a diatomic gas at 0°C and 2 atm is 1g. Calculate the weight in g of one atom.

Answer 1

For given gas T = 273 K, V = 350 ml

p = 2 atm, W = 1 g

∴ pV = (W/m)RT = 2 x 350/1000

= 1/m x 0.0821 x 273

Therefore, molecular mass 'm' of gas = 32.02

Therefore, atomic mass of gas = (mol.mass/2)  [∵ gas is diatomic]

= 32.02/2 = 16.01

Now 6.023 x 10²³ atoms weigh 16.01 g

1 atom weighs = {16.01}/{6.023 x 10²³} = 2.66 x 10^-23 g