Problem 8.29

[Cristian Carrasco 1F]

Which one has greater enthalpy, NO or NO2 and Why?

[CameronJohari1J]

NO2 has greater enthalpy than NO because there are more bonds that require more energy thus greater enthalpy.

[Jessica Patzlaff 1A]

NO2 would have a higher molar heat capacity because there are a greater number of atoms within the molecule, and thus more possible outlets to absorb energy such as in vibrational and rotational energy. As a result, it would take more energy to increase the temperature of an entire molecule of NO2 as opposed to NO.

[Kaelie Blanes-Ronda 2L]

In the textbook in section 8.10 there is a chart comparing linear and bent molecules with their molar heat capacities. "The molar heat capacity of NONlinear molecules is HIGHER than linear molecules because they can rotate about 3 rather than 2 axes." If you were to draw the lewis structure of NO you would see that it is linear whereas NO2 is bent which means it has a higher molar heat capacity and thus requires a greater level of enthalpy/energy to break bonds.

[Jessica Nunez 1I]

NO2 would have higher molar heat capacity because heat capacity increases with molecular complexity. This means that as more atoms are present in the molecule, there are more possible bond vibrations that can absorb added energy.