Calculate the volume (in mL) that a 1.55 x 10⁻³ mol sample of a gas will occupy at 290 K and a pressure of 126 torr.

Answer 1

Use the ideal gas law: PV = nRT and solve for V

P = pressure in atm = 126 torr x 1 atm / 760 torr = 0.1658 atm

V = volume in L = ?

n = moles = 1.55x10^-3 mols

R = gas constant = 0.0821 Latm/Kmol

T = temperature in Kelvin = 290K

V = nRT/P

V = (1.55x10^-3 mols)(0.0821 Latm/Kmol)(290K) / 0.1658 atm

V = 0.223 L

Converting to mls, we have..

0.223 L x 1000 mls / L = 223 mls (3 sig. figs.)