Stoichiometry Involving Gases

Many chemical reactions involve gases. Section 9.5 gave several equations that relate the mass of a gas (in terms of moles) to its volume, temperature, and pressure. These relationships can be applied to stoichiometric problems involving gases.

Example: What volume of carbon dioxide at 37°C (body temperature) and 740 torr is produced by the metabolism of 1.0 g ethyl alcohol (C2H5OH)? The balanced equation is: Solution To sove this problem find the number of moles of CO2 formed. Then use the ideal gas equation to convert from the number of moles of carbon dioxide to a volume; Wanted Liters (V) of CO2 at 37°C and 740 torr Given 1.0 g C2H5OH Conversion factors 1 mol C2H5OH = 46.1 g C2H5OH 1 mol of C2H5OH yields 2 mol CO2 37°C = 310 K Arithmetic equation Substiuting this value into the ideal gas equation gives: Answer