Question

Density of a gas is found to be 5.46g/dm3 at 27degree at 2 bar pressure . Calculate the density at stp

Answer 1

According to the question, T = 27°C = 27 + 273 = 300 K , P = 2 bar

(Temperature is always taken in K-Scale)

At STP, T = 273 K, P = 1 atm ≈ 1 bar

Let mass of gas = 5.46 g then volume = 1 dm∧3  

For any gas, PV/T is constant

2 x 1 / 300 = 1 x V / 273

V = 1.82 dm∧3

Density = Mass / Volume (Mass is always constant)

= 5.46/1.82 = 3 g/dm∧3