Decomposition reaction: CH2=CH2(g)---> CH4(g) + C (Graphite)

If the decomposition begins at 10c and 40.0 atm with a gas density of .215 g/ml and the temp increases by 950K. (a) what is the final temperature of the confined gas (ignore volume of graphite and use the van der waals equation)?

I have this for van der waals: (P + (n^2a/V^2)) * (V -nb) = nRT

I know my a and b constants. a = 2.25, b = .0428.

Do I need to use the density to find n? .215g/ml = 215g/L. Can I assume that there is 1 Liter in my equation. If I do that then there are 13.4 moles in the gas.

This would make my equation (P + (3.14^2*2.25/1^2)*(1-3.14*.0428)= 3.14*.0821*1233

This equation doesnt seem right. Can anyone help me figure out where I'm making my mistakes?

1 answer

anyone?