Question

A sample of an ideal gas has a mass of 0.311 grams. its volume is 0.225 l at a temperature of 55oc and a pressure of 1.166 atm. find its molar mass.

Answer 1

Answer:

The molar mass of the gas is 31.9 g/mol

Explanation:

Step 1: Data given

Mass of the gas = 0.311 grams

Volume = 0.225 L

Temperature = 55.0 °C

Pressure = 1.166 atm

Step 2: Calculate moles

p*V = n*R*T

⇒ p = the pressure of the gas = 1.166 atm

⇒ V = the volume of the gas = 0.225L

⇒ n= the number of moles of gas = TO BE DETERMINED

⇒ R = the ideal gas constant = 0.08206 L*atm/K*mol

⇒ T = the temperature = 55.0 °C = 328 Kelvin

n = (p*V)/(R*T)

n = (1.166*0.225)/(0.08206*328)

n = 0.009747

Step 3: Calculate the molar mass

Molar mass = mass / moles

Molar mass = 0.311 grams / 0.009747

Molar mass = 31.9 g/mol

The molar mass of the gas is 31.9 g/mol

Answer 2

Use pv=nrT


where p is the pressure,
v is the volume,
n is the number of mole (which can be equal to mass /mr),
T is the temperature in kelvin,
and r is (molar constant) = 8.31 (units)