Question

at 27° Celsius hydrogen is linked through tiny hole into a vessel for 20 minutes another unknown gas at the same temperature and pressure as that of H2 is linked through the same hole for 20 minutes after the fusion of the gases the mixture exerts a pressure of 5 ATM best to content of the mixture is 0.75 moles if the volume of the container is 5 litre what is the molecular weight of the unknown gas.(R=1÷12lt.atm/mol

Answer 1

Using gas equation; PV = nRTTotal no. of moles of gases in the mixture (n)= PV/RT = 6 *3/0.0821 *300 = 0.7308 mol.Thus no. of moles of unknown gas = 0.7308 – 0.7= 0.0308 mol.Now we know thatr1/r2 = moles of hydrogen gas/moles of unknown gas = 0.7/0.0308Also we know that r1/r2 = √M2/M1∴ M2 = (r1/r2)2M1 or M2 = (0.7/0.0308)2 * 2 = 1033