A sample of O2 gas occupies a volume of 871 mL at 25 °C. If pressure remains constant, what would be the new volume if the temperature changed to:
New volume
(a) -5 °C
(b) 95 OF
(c) 1095 K

Explanation:

The pressure and the number of moles are constant, so, to calculate the volume, we can use Charles' Law.

(a) Volume at -5 °C

Data:

V₁ = 871mL; T₁ =  25 °C

V₂ = ?;         T₂ =   -5 °C

Calculations:

(i) Convert temperatures to kelvins

T₁ = ( 25 + 273.15) K = 298.15 K

T₂ =   (-5 + 273.15) K = 268.15 K

(ii) Calculate the new volume

(b) Volume at 95 °F

95 °F = (95 - 32) × 5/9 = 63 × 5/9 = 35 °C

35 °C = (35 + 273.15) K = 308.15 K

(c) Volume at 1095 K