An evacuated glass vessel weighs 50 g when empty, 148 g when filled with a liquid of density 0.98 g/ml and 50.5 g when filled with an ideal gas at 760 mm Hg at 300K. Determine the molecular weight of the gas.

An evacuated glass vessel weighs 50 g when empty, 148 g when filled wi

1.	An evacuated glass vessel weighs 50 g when empty, 148 g when filled with a liquid of density 0.98 g/ml and 50.5 g when filled with an ideal gas at 760 mm Hg at 300K. Determine the molecular weight of the gas.
Answer» Weight of the evacuated glass vessel = 50 g Weight of LIQUID = 148 g; Liquid of density = 0.98 g/ML When filled with ideal gas its weight is 50.5 g with gas at 760 mm Hg at 300 K Actual weight of the liquid = 148 - 50 = 98 g Liquid volume = 100 ml The vessel volume = vessel of 100 ml contain “ideal gas” at pressure and temperature of 760 mm Hg and 300 K RESPECTIVELY. Weight of ideal gas = 50.5 - 50 = 0.5 g Using, PV = nRT We Know that, So, (We know that pressure of ideal gas is 760mm Hg. Given pressure is also 760 mm Hg. So 760/760 = P = 1) Therefore, the “molecular weight” of gas (m) = 123 g/mol