Question

calculate the density of SO2 gas at STP
calculate the density of CH4 gas at 1.5 atm and 15degree Celsius

Answer 1

For SO₂

As we know that at STP condition(Pressure=1 atm and Temperature= 273 K), one mole of any gas(assuming ideal behaviour) occupy 22.4 L. So, 1 L of SO2 contains (1/22.4) mol gas. Molecular mass of SO2=32+2*16 = 64 g/mol

Hence density of SO2 gas = (1/22.4) mol * 64 g/mol per litre = 2.86 g/L

For CH4

From ideal gas equation, PV = nRT

We have,

P = 1 atm, let volume,V = 1 L, T = (273 + 15) K = 288 K, R = 0.082 L-atmK^-1mol^-1

Hence number of moles, n(per litre) = PV/RT = 0.07 mol

Molecular mass of CH4 = 16 g/mol

Hence density of CH4(in g/L) = 0.07*16 = 1.07 g/L