what volume of carbon dioxide is produced from the reaction of 12.8 liters of oxygen with excess carbon disulfide?

Answer 1

CS2 + 3O2 ==> CO2 + 2SO2
12.8 L O2 x (1 mol CO2/3 mols O2) = 12.8 x 1/3 = ?
Note that I made the conversion from O2 to CO2 directly with Liters and did not go through mols. How can I do that? When everything is in the gaseous state, then we can use that short cut because PV = nRT. Since P, R and T are constant, then V is proportional to n so going through n is not necessary.