A gas has a volume of 91 ml at a temperature of 91°C. This gas is kept at constant pressure but its temperature is reduced to 0.0°C. At this temperature the volume of the gas will be approximately

2 answers

Charles Law?

V1/V2=T1/T2

work it in Kelvins, not Celcius.
(P1V1)/T1 = (P2V2)/T2
Since pressure is constant, just ignore it (either omit it from the formula OR put a 1 for both P1 and P2). Don't forget to use Kelvin for T.