heat capacity

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Ricky Ma DIS 4E
Posts: 72
Joined: Fri Sep 28, 2018 12:27 am

heat capacity

Postby Ricky Ma DIS 4E » Tue Feb 05, 2019 4:51 pm

it heat capacity and enthalpy of vaporization/sublimation the same thing?? Are they closely related conceptually?

monikac4k
Posts: 56
Joined: Fri Sep 28, 2018 12:25 am

Re: heat capacity

Postby monikac4k » Tue Feb 05, 2019 4:56 pm

Heat capacity is the amount of energy (in the form of heat) required to raise the temperature of a specific substance one degree C.
e.g. the amount of energy required to raise the temperature of a sample of water is 4.184 J*g^-1*C^-1.
The enthalpy of vaporization is the amount of energy (in the form of heat) required for a substance to change from the liquid phase to the gas phase.
Additionally, the enthalpy of sublimation in the amount of energy (in the form of heat) required for a substance to change from the solid phase to the gas phase.
e.g. the enthalpy of vaporization for water is 40.7 kJ/mol; 40.7 KJ of heat are required to cause one mole of H20 in the liquid phase to transfer over to one mole of H20 in the gaseous phase.
Hope this helps clarify things.

Ray Guo 4C
Posts: 90
Joined: Fri Sep 28, 2018 12:15 am

Re: heat capacity

Postby Ray Guo 4C » Tue Feb 05, 2019 4:57 pm

I think they are the same, except the enthalpy ones are often in J per mol while specific heat capacity can be in J per mole or J per gram. The value of the enthalpy ones can also change when you change the stoichiometry of the reaction of vaporization/sublimation.


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