711. Problem 49.21 (RHK) In terms of Einstein’s theory of heat capacity, we have to find (a) the molar heat capacity at constant volume of a solid at its Einstein temperature, and express our answer as a percentage of its classical value of 3R. (b) We have to find the molar internal energy at the Einstein temperature, and express our answer as a percentage of its classical value of . |
Solution: Click For PDF Version The molar internal energy of a solid, according to Einstein’s theory of heat capacity, can be expressed as
in which , where is the Einstein temperature.
Specific heat at constant volume
Therefore, the molar heat capacity at constant volume of a solid at its Einstein temperature will be It is 33.8% of its classical value 3R. (b) The molar internal energy at the Einstein temperature will be which is 58.2% of its classical value . |