1. The problem statement, all variables and given/known data One mole of CO and 1/2 mole of oxygen are mixed and the products consist of CO2, CO, O2, and O. Write the atom balance for C and O. 2. Relevant equations Mass conservation 3. The attempt at a solution 1/2(O2)+CO2 -> aCO2 +bCO+cO2 +dO. a, b, c, d are unknowns. I make a table: Element Reactants Products C 1 a+b O 2 2a+b+2c+d Its unsolvable. 2 equations and 4 unknowns. But the answer is CO2 <-> CO+1/2(O2) How?