Heat Capacity at constant Volume & Pressure - University Physics

In this video, we apply the first law of thermodynamics to an ideal gas to derive what the heat capacity at constant volume and constant pressure is.
We also introduce Enthalpy H and explain the significance.
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[@willm6598]

I can't belive this video is real, this is exactly what I have been trying to understand

[@aldanadagimpaulos7511]

thank you sir that was very helpful

[@FijiWater1227]

Thank you this was very interesting

[@rk__vilog5402]

Such a nice teaching method sir

[@pazzy768]

Thank you, glad it helped!

[@jeffbrunswick5511]

Why does R = Cp - Cv?

[@pazzy768]

Cp is 5/2Nk_B and Cv is 3/2Nk_b, therefore subtract the two, and you get Nk_B which is nR

[@jeffbrunswick5511]

@@pazzy768 Thanks for your reply, but I wasn't referring to the mathematical relationship. Why is the heat capacity when measured at atmospheric pressure exactly 8.314 J K-1 higher than when measured at constant volume?

[@pazzy768]

@@jeffbrunswick5511 Had a look online and found “Mayer’s Relation” on Wikipedia. It seems to be an empirically found property of materials and not necessarily ideal gasses en.m.wikipedia.org/wiki/Mayer%27s_relation

[@jeffbrunswick5511]

@@pazzy768 I'm thinking that it is the work done by an ideal gas when it is allowed to expand, hence why heat capacity at constant pressure is greater by exactly 8.314 J K-1 mol-1 for ideal gases. See here: en.wikipedia.org/wiki/Table_of_specific_heat_capacities This would imply that you would have to remove R from the ideal gas law when calculating pressure changes in an autoclave. Hard to believe that this would be true, but I don't see how else to explain it.