Question

A gas occupies a volume of 143 mL at 35.0 °C and .5 atm. What is the volume of the gas at standard temperature and pressure of 1 atm and 0°C.

A.0 mL
B.8.50 x 10-4 mL
C.63.4 mL
D.557.7 mL

Answer 1

Use the combined gas law (convert temperatures to Kelvin first).

P1V1/T1 = P2V2/T2
P1 = 0.5 atm
V1 = 143 mL
T1 = 35.0°C = 308 K
P2 = 1 atm
V2 = ?
T2 = 0°C = 273 K

Solve the equation for V2 and you get:
V2 = P1V1T2/T1P2 = (0.5 atm)(143 mL)(273 K) / (308 K)(1 atm) = 63.4 mL

C. 63.4 mL