Heating gases at constant pressure or constant volume?

[twiztdlogik]

if i was to heat a gas [any gas] by 10 degrees celcius, using the smallest amount of heat energy, would i be better off heating the gas at constant pressure or constant volume. i think constant pressure, however i don't know how to justify my answer...

cheers

 

[dynamicsolo]

You'll want to look for the specific heat capacity of an ideal gas at constant volume and at constant pressure, and compare them. The smaller heat capacity means it takes less heat to raise the temperature of the gas by a chosen amount.

 

[Redbelly98]

Alternatively, you could think about extra energy being lost or gained, for the cases where pressure is constant or volume is constant.