Page 1 of 1

### Temperature Relation

Posted: Wed Feb 14, 2018 11:55 am
Can someone please explain the relationship between temperature and internal energy ?
Also, the relationship between temperature and entropy?
Thanks

### Re: Temperature Relation

Posted: Wed Feb 14, 2018 1:13 pm
Relationship between T and delta U:

$\Delta U = q$ (assuming no work is done)

If you increase heat added (increase q) then delta U increases.

Relationship between T and delta S:

delta S$\Delta S __{T_{1} \rightarrow T_{2}} = nC(\ln T_{2} - \ln T_{1})$

If you look at the natural log graph:

If $T_{2}> T_{1}$ ($\Delta T> 0$), $\ln T_{2} - \ln T_{1}$ is positive and $\Delta S$ is positive.
If $T_{2}> T_{1}$ ($\Delta T< 0$), $\ln T_{2} - \ln T_{1}$ is negative and $\Delta S$ is negative.

### Re: Temperature Relation

Posted: Fri Feb 16, 2018 1:13 am
Also the internal energy of an ideal gas is determined by the temperature so if there's no change in temperature there can be no change in internal energy for the gas.