Question

A 2.53 gram sample of an unknown gas is found to occupy a volume of 2.00 L at a pressure of 0.804 atm and a temperature of 37 °C. The molar mass of the unknown gas is__ g/mol.

Answer 1

we have:

P = 0.804 atm

V = 2.0 L

T = 37.0 oC

= (37.0+273) K

= 310 K

find number of moles using:

P * V = n*R*T

0.804 atm * 2 L = n * 0.08206 atm.L/mol.K * 310 K

n = 6.318*10^-2 mol

mass of solute = 2.53 g

we have below equation to be used:

number of mol = mass / molar mass

6.318*10^-2 mol = (2.53 g)/molar mass

molar mass = 40.04 g/mol

Answer: 40.0 g/mol