10.8 NOTES Gas Stoichiometry

V. Gas Stoichiometry (volume relationship holds for gases ONLY) Avogadro’s Principle states that equal volumes of gases at the same temperature and pressure contain equal numbers of particles. Therefore, coefficients in a balanced equation represent not only molar amounts, but also relative volumes of gaseous substances.

A. Calculations involving volume only CH4(g) + 2O2(g)  CO2(g) + 2H2O(g) *Start w/ balanced equation!! 1 L CH4(g) + 2 L O2(g)  1 L CO2(g) + 2 L H2O(g) * Volume ratios can be set up for any pair of gases  

Examples: 1. How many liters of CH4(g) are needed to produce 26 L of H2O(g)? CH4 : H2O = 1:2  13L CH4(g)  

2. Calculate the volume of O2 needed to completely combust 2 2. Calculate the volume of O2 needed to completely combust 2.36L of CH4. 2.36L CH4 x 2 L O2 = 4.72L O2 1 L CH4