Question

Density of a gas is found to be 5.46 g/dm³ at 27 °C at 2 bar pressure. What will be its density at STP?

Answer 1

We know that, for an ideal gas
Density d = P × M/ RT
According to the question,
5.46 = 2 × M/ R × 300 ….. (1)
and, At STP, d = 1 × M/R × 273 …(2)
Dividing equation (ii) by (i)
d/5.46 = (1 × M/273 × R) × (300 × R/2 × M)
d = 300 × 5.46/ 273 × 2 = 3.00 g/dm³
Hence, the density of the gas at STP will be 3 g dm^-3.