2 Stoichiometry Stoichiometry Greek for “measuring elements” Pronounced “stoy kee ahm uh tree”Definition:Calculations of the quantities in chemical reactions, based on a balanced equation.
3 StoichiometryThere are 4 ways to interpret a balanced chemical equationMolesCoefficient ratiosParticles6.02 × 1023 particles/moleMassMolar mass/moleVolume22.4 L/mole
4 StoichiometryMass and atoms are ALWAYS conserved, however, molecules, formula units, moles, and volumes will not necessarily be conserved
5 Stoichiometry 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
6 Stoichiometry 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
7 Stoichiometry __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