Posted by shery on .
a mixture of 0.156 moles of C is reacted with 0.117 moles of O2 in a sealed, 10.0L vessel at 500K, producing a mixture of CO amd CO2. The total pressure is 0.640 atm. what is partial pressure of CO?

chem 
DrBob222,
3C + 2O2 ==> 2CO + CO2
If total pressure at the end is 0.640 atm (the problem doesn't say 0.640 at the end of the reaction but I'm assuming that) then use PV = nRT and solve for n = total moles. I get about 0.1 mol total.
Since CO2 and CO are produced in the ratio of 1:2, then
2*molsCO + 1*mol CO2 = 0.1
2x + x = 0.1 and
x = about 0.033 and 2x = about 0.67. These are approximate; you should use more significant figures than that.
Then pCO = XCO*Ptotal.