Positive vs Negative Heat Capacities

[Emma Healy 2J]

Hi! Is it possible to have a negative heat capacity? Or does it always have to be a positive value?

[Ashley Ko 3I]

Hi! I believe that heat capacity has to always be a positive value since it represents the amount of heat required (adding heat so endothermic and a positive value) to raise the temperature of the compound by 1 temperature unit (typically either K or C). The same reasoning applies to specific heat capacity (amount of heat required to raise one mol or g of a compound by 1 temperature unit). Hope this helps!

[Yun Su Choi 3G]

Heat capacities should be positive because if you look at q=mcT, moles and c should always be positive so that the sign of q is dependent on change of temperature. If T is positive, q would be positive, representing the absorbance of heat. If T is negative, q would be negative, indicating a release of heat energy.

[Grace_Remphrey_2J]

Yes I'm pretty sure, heat capacity always has a positive value since it is the amount of energy (heat) required to raise the temperature of the system. Hope this helps!