According to the task, you are proveded with patial pressure of CO2 and graphite, and here is complete solution for the task :
At first you have to find n1 =moles of CO2 and n2 which are moles of C
<span>The you go :
</span>
n1 n2 0
-x -x +2x
After that you have to use the formula
Then you have to solve x, and for that you have to use <span>RT/V
And to find total values:</span>
I am absolutely sure that this would be helpful for you.