A sample of gas is held in a 793 mL vial at 13.0 atm and 69.1 degrees Celcius. How many mol gas are there in the vial?

Answer 1

Ideal gas law: PV = nRT

P = pressure = 13.0 atm

V = volume in L = 793 ml x 1 L / 1000 ml = 0.793 L

n = moles = ?

R = gas constant = 0.0821 Latm/Kmol

T = temp in Kelvin = 69.1ºC + 273.15 = 342.25K

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

n = PV/RT

n = (13.0)(0.793) / (0.0821)(342.25)

n = 0.367 moles (3 sig. figs.)