When carbon is burned in air, it reacts with oxygen to form carbon dioxide. When 14.4g of carbon were burned in the presence of 54.3 g of oxygen, 15.9 g of oxygen remained unreacted. What mass of carbon dioxide was produced?

C(s) + O2(g) --> CO2(g)12g (C) 50.8g (O2) initial amounts0g(C) 18.8g(O2) amounts when reaction completeThat means that C was the limiting reactant, and the amount of CO2 is based on the amount of carbon that burned. Covert 12 grams of carbon to moles. The moles of CO2 will be the same, since they are in a 1:1 mole ratio. Then convert the moles of CO2 to grams.12g C x (1 mol C / 12.0 g C) x (1 mol CO2 / 1 mol C) x (44.0g CO2 / 1 mol CO2) =44 g of CO2