# Homework Help: Heat added to gas

1. Jul 30, 2014

### physicsgirl199

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

0.20 g of hydrogen gas are held in a rigid container. The temperature of the gas is changed from 200 K to 320 K. How much heat is needed

2) A gas at p = 80kPa and T = 350K has a mass density of 8.65×10−2kg/m3 . find the V_rms

2. Relevant equations

E_thermal = 3/2nRT

2) v_rms = √(3k*T)/m

3. The attempt at a solution
tried doing this equation and got an answer of 30 which is wrong, not really sure if im even on the right track any guidance is appreciated!

im not even sure how to start this problem, im not sure the reason mass density is given, im assuming to find mass but im confused.

2. Jul 31, 2014

### Simon Bridge

... well there are no units for a start, and you did not say which equation you used or which question you are answering.

... hint: what is "specific heat"?
... you'd like to use the second equation right? But you don't know the temperature or the particle mass. Can you use the pressure and the density in combination to help you find these things? Can you find another equation that relates the rms velocity with the density and pressure?