# What is the temperature of the gas?

1. May 7, 2012

### Bigworldjust

1. The problem statement, all variables and given/known data

A gas of 8.00×10^19 atoms or molecules has 0.500 J of thermal energy. Its molar specific heat at constant pressure is 20.8 J/mol K.

2. Relevant equations

T = 0.5/(N*specific heat)

3. The attempt at a solution

I divided 8.00*10^19 by Avogadro's Constant to get the number of moles. Than I did .5/(N*20.8 J/mol K) and got 181 K. But that seems to be incorrect. Anyone know why?

2. May 7, 2012

### ehild

Why does it seem incorrect?

Edit: The molar heat at constant pressure is given!

ehild

Last edited: May 7, 2012
3. May 7, 2012

### vela

Staff Emeritus
You're using the wrong specific heat.

4. May 7, 2012

### Bigworldjust

What specific heat do I use?

5. May 7, 2012

Use Cv.

ehild

6. May 7, 2012

### Bigworldjust

Wait how do I calculate Cv?

7. May 7, 2012

### vela

Staff Emeritus
That's something you need to figure out. The relationship between cp and cv is surely talked about in your textbook.

8. May 7, 2012

### Bigworldjust

Thanks, I got it now.

Last edited: May 7, 2012