Question

7. At STP, which of the gas weighs the most? A) 22.4 L of H2 B) 22.4 L of O2 C) 22.4 L of SO2 D) 22.4 L of N2 E) 22.4 L of CO2

Answer 1

In order to obtain the value of Mass of each gas we will apply Ideal gas law to each cases

and obtain the number of moles of each case and multiply it with molar mass to obtain the mass

By ideal gas law

P V= n R T

P = bar

V =22.4 Liter

R = 0.08314 bar L k-1 MOL-1

T = 273.1 K

Hence,

n = (PV/RT)

Now for all of the cases the number of moles will be same since all the parameters are same ,the only difference will be the value of molar mass

So lets say this value is a constant ( PV/RT) = K

Now

mass = Molar mass * K

From above equation we can derive that higher the molar mass higher will be the weight

From the given data

Molar mass of H2 = 2 g/mol

Molar mass of O2 = 32 g/mol

Molar mass SO2 = 64 g/mol

Molar mass n2 = 28 G/MOL

Molar mass CO2 = 44 g/mol

Since the value of molar mass of SO2 is higher , it will weigh the most

Hence, answer is option C) 22.4 Liter of SO2