Calculating Molar Mass of a Gas

Answer:

Molar Mass = 120 g/mol

Explanation:

Data Given:

Volume = V = 0.0650 L

Temperature = T = 547 °C = 820.15 K

Pressure = P = 70.5 kPa = 0.695 atm

Gas Constant = R = 0.082057 L.atm.mol⁻¹.K⁻¹

Formula Used:

Assuming that the gas is ideally then according to ideal gas equation,

P V = n R T

Solving for n,

n = P V / R T

Putting Values,

n = (0.695 atm × 0.0650 L) ÷ (0.082057 L.atm.mol⁻¹.K⁻¹ × 820.15 K)

n = 6.71 × 10⁻⁴ moles

Now, Knowing that,

Moles  =  Mass / M.Mass

Or,

M.Mass = Mass / Moles

Putting values,

M.Mass = 8.06 × 10⁻² g / 6.71 × 10⁻⁴ mol

Molar Mass = 120 g/mol