Help me please with the answer

Question

What is the molecular weight of a gas if 372 mL has a mass of .800 g at 100 °C and 800 torr?

____unit:______

Answer 1

Use the ideal gas law to find the number of moles of the gas

PV = nRT

P = pressure = 800 torr x 1 atm / 760 torr = 1.05 atm

V = volume in liters = 372 mls = 0.372 L

n = moles = ?

R = gas constant = 0.0821 Latm/Kmol

T = temperature in Kelvin = 100C + 273 = 373K

Solving for n (moles), we have...

n = PV/RT = (1.05)(0.372) / (0.0821)(373)

n = 0.0128 moles

molar mass of gas = gram / moles

molar mass = 0.800 g / 0.0128 moles

molar mass = 62.5 g / mole