2Stoichiometry Stoichiometry Greek for “measuring elements” Pronounced “stoy kee ahm uh tree”Definition:Calculations of the quantities in chemical reactions, based on a balanced equation.
3StoichiometryThere are 4 ways to interpret a balanced chemical equationMolesCoefficient ratiosParticles6.02 × 1023 particles/moleMassMolar mass/moleVolume22.4 L/mole
4StoichiometryMass and atoms are ALWAYS conserved, however, molecules, formula units, moles, and volumes will not necessarily be conserved
5Stoichiometry Mole to Mole Conversions The coefficients tell us how many moles of each substance2Al2O3 ® 4Al + 3O2Molar RatiosEach time we use 2 moles of Al2O3 we also make 3 moles of O2.2 moles Al2O33 mole O2or
6Stoichiometry 2Al2O3 ® 4Al + 3O2 Mole to Mole Conversions Practice How many moles of O2 are produced when 3.34 moles of Al2O3 decompose?2Al2O3 ® 4Al + 3O23.34 mol Al2O32 mol Al2O33 mol O2=5.01 mol O2
7Stoichiometry __Na + __H2O ® __NaOH + __H2 Mole to Mole Conversions PracticeHow many moles of H2 are produced when 2.05 moles of Na react with water?__Na + __H2O ® __NaOH + __H22.05 mol Na2 mol Na1 mol H2=1.03 mol H2