Question

What is the volume of 2.0 g of cs2 vapor (molar mass = 76.15 g/mol) at 70°c and 726 mm hg? l?

Answer 1

To find the volume occupied by 2.0 g of CS₂ gas we can use the ideal gas law equation 
PV = nRT
where P - pressure - 726 mmHg x 133 Pa/mmHg = 96 558 Pa
V - volume 
n - number of moles = mass / molar mass
number of CS₂ moles = 2.0 g / 76.15 g/mol = 0.026 mol
R - universal gas constant - 8.314 Jmol⁻¹K⁻¹
T - temperature in kelvin - 70 °C + 273 = 343 K
substituting these values in the equation 
96 558 Pa x V = 0.026 mol x 8.314 Jmol⁻¹K⁻¹ x 343 K
V = 0.768 L
the volume occupied is 0.768 L