Ideal Gas Law and Stoichiometry Using moles and balanced reactions to relate to gas reactions
Ideal Gases and Moles We often are concerned with finding the amounts of reactants or products in a reaction and they may be gases. The ideal gas law can be used to find the moles of a chemical in a reaction given P, V, and T. Mole ratios can then be used to apply the information to a chemical reaction and find out more information. If a reaction is done at STP then we can use 22.4 L= 1 mol of gas as a conversion. Then the ideal gas law does not need to be used.
Example #1 Auto air bags are inflated by nitrogen gas generated by the rapid decomposition of sodium azide, NaN3. 2 NaN3 (s) 2 Na (s) + 3 N2 (g) If an air bag has a volume of 36 L and is to be filled with nitrogen gas at 1.15 atm and 26.0 ˚C, how many grams of NaN3 must be decomposed?
Example #2 2 C8H18(l) + 25 O2(g) 16 CO2(g) + 18 H2O(g) If 3035 grams (1 gallon) of gasoline are burned, what volume of carbon dioxide is produced if the pressure is 0.953 atm, and the temperature is 35.0°C?
Example #3 CH4(l) + 2 O2(g) CO2(g) + 2 H2O(g) Methane is burned in oxygen at STP. How many liters of CO2 are produced when 35.4 L of oxygen is reacted?