Entropy Question

1. Jul 20, 2004

Jerzey2Atl

Hi, this is my first time using this forum. I have a question dealing with entropy and thermodynamics.

Here goes:

According to Debye’s law, the molar heat capacity at constant volume of a
diamond varies with temperature according to the relation

Cv = (12*pi^4*R / 5) x (T / TD)^3

where TD = 2230 K. For a diamond of mass 1. 20 g, what is its entropy change when it is heatedat constant volume from 10. 0 K to 350 K? The molar mass of carbon is 12. 0 g/mol.

I know Ih ave to first find the molar mass, but I am not sure of which form of the entropy equation to use. Any help is appreciated.

2. Jul 20, 2004

PureEnergy

To solve the problem you can use this equation to find the molar entropy

$$\Delta S = \int_{T_1}^{T_2} C_v \frac{dT}{T}$$

Multiply this result by the numer of moles (1.2/12) to get entropy in terms of energy/time.

3. Jul 21, 2004

Jerzey2Atl

Thanks a lot....imma try this.