What would be the density of h2 gas at 500◦c and 0.76 atm?

=  0.02414 g/L

Using the formula;

PV = nRT, where P is the pressure, V is the volume, n is the number of moles , T is the temperature and R is the gas constant, 0.08206 L. atm. mol⁻¹.

But; PV = nRT = P/RT =n/V and n = mass/molar mass

Thus;

P/RT = n/V = (Mass/molar mass)/V

Therefore; (P/RT)× molar mass = mass/V = density

Thus;

Density = (0.76 × 2.015 g/mol)/ (0.08206 ×773.15 K)

            =  0.02414 g/L