An ideal gas occupies a volume, v at 100 degree celcius. If the gas pressure is held constant, by what factor does the volume change if the kelvin temperature is doubled

K = C + 273 = 100 + 273 = 373o.

T1/V1 = T2/V2.
373/V1 = (2*373)/V2.
373(V2/V1) = 2*373
V2/V1 = 2.
The vol. changed by a factor of 2.