The ideal gas law PV = nRT relates pressure P, volume V, temperature T, and the number of moles of a gas, n. The gas constant R equals 0.08206 L·atm/(K·mol) or 8.3145 J/(K·mol). The equation can be rearranged as follows to solve for n: n = PV/RT. This equation is useful when dealing with gaseous reactions because stoichiometric calculations involve mole ratios.
Butane, C4H10, is a component of natural gas that is used as fuel for cigarette lighters. The balanced equation for the complete combustion of butane is 2C4H10(g) + 13O2(g) → 8CO2(g) + 10H2O(l). At 1.00 atm and 23 °C, what is the volume of carbon dioxide formed by the combustion of 1.60 g of butane?