1. The problem statement, all variables and given/known data 5,00 moles of graphite and 5,00 moles of oxygen gas are stored in a metal bottle. The temperature is raised until the graphite starts burning. The burning produces a mixture of CO and CO2 gases in the vessel. After the temperature had returned to it's original value (after the reaction), the pressure inside the bottle had increased by 17%. Find out the molar fractions of each of the gases inside the bottle when all of the graphite is used up in the reaction. Correct answers: xO2 = 0,145; xCO = 0,291; xCO2 = 0,564 2. Relevant equations xi = pi/ptotal = ni/ntotal, where x = molar fraction. Dalton's law: Sum(pi) = ptotal pV = nRT 3. The attempt at a solution I started out by forming the chemical equation: 3C + 2O2 -> 2CO + CO2 From this I calculated that nCO = (2/3)nC = 10/3 mol and nCO2 = (1/3)nC = 5/3 mol ( since we know that C is the limiting reactant). We can also see that the amount of used up oxygen is nO2 = nCO = 10/3 mol, so the amount oxygen gas remaining in the bottle after the reaction is nO2g = 5mol - nO2 = 5/3 mol, so the total amount of gas in the bottle (after the reaction) would be 20/3mol. Next I assumed that the volume of C is negligible, so V is constant. T is also constant between the initial and final stages.This means that: V0 = V1 <=> n0/p0 = n1/p1 = n1/1,17p0 (From pV = nRT). => n1gas = 1,17n0gas = 1,17 * 5 mol = 5,85 mol. However, the value of n1gas does not equal the total amount of moles I got from adding up the individual amounts of the different gases, and I'm not sure what to do next. I don't see how I could use Dalton's law to my advantage here, since i can't actually calculate the pressures because I know nothing about the temperature or the volume of the bottle. Can anybody point me in the right direction? I am aware that I might not even need the actual values of the pressures or moles since I'm supposed to find the percentages, but I just don't know how to proceed.