# Quantum Um vs Classical Um

## Homework Statement

Show that the contribution to the total energy from molar internal energy Um reverts to the classical expression at high T.

## Homework Equations

Classical: Um = 3NakT Quantum Um = 3NAhv/e^(hv/kT)-1

## The Attempt at a Solution

Manipulating variables- E=hv
Quantum rearranging: hv/kT= ln(3Nahv)-ln(Um)
Very confused on what is meant by total energy though. Is that supposed to be E+Um?

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I am assuming that for high T you can manipulate $e^{\frac{h \nu}{k T}}$. Try this.