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molar heat capacity

Posted: Mon Jan 18, 2016 3:03 pm
by Dahriel Aron 3A
What would cause one molecular substance to have a higher molar heat capacity than another molecular substance?

Re: molar heat capacity

Posted: Mon Jan 18, 2016 3:55 pm
by Tiffany Chen 2E
Molecules with hydrogen bonding usually have higher molar heat capacities. Substances with strong hydrogen bonds, such as water or ammonia, take the absorbed thermal energy and store it as potential energy within the hydrogen bonds. Thus, it takes more energy to increase the kinetic energy (or increase the temperature) of the molecular substance.

In addition, substances with more complex chemical structures will also tend to have higher heat capacities for a similar reason. More complex molecules have more bonds that vibrate and consequently absorb added thermal energy, making it more difficult to increase the temperature.

Re: molar heat capacity

Posted: Mon Jan 18, 2016 5:59 pm
by Omar Habib 3L
In general, heat capacity increases with molecular complexity. Thus, more atoms lead to more possible bond vibrations that absorb added energy.

For example: NO2 would have a higher heat capacity than NO.