Drill: How many atoms are in 3.2 kg Fe2O3?
The quantitative study of chemical reactions Stoichiometry The quantitative study of chemical reactions
Stoichiometric Steps Set up & balance rxn Change stuff given to moles Change moles given to ask Change what’s asked for to the proper unit
Step 1 Determine products of a reaction if they are not given Balance the reaction
Step 2 Use molar conversion to change whatever is given to moles
Step 3 Use the molar ratio from the balanced reaction to convert the moles of what is given to the moles of what’s asked for.
Step 4 Use molar conversions to change the moles of what is asked for to the proper unit
Calculate the volume of NH3 formed at STP when 6 Calculate the volume of NH3 formed at STP when 6.0 kg of H2 react with excess N2 to form NH3
Drill: Calculate the number of molecules of oxygen gas required to burn 3.0 ng of C5H10O5
Chm II: Calculate the mass of Lead(II)iodide formed when 66 Chm II: Calculate the mass of Lead(II)iodide formed when 66.2 g of lead (II)nitrate is combined with excess potassium iodide
Chm II: Calculate the mass of MgCO3 formed when 18 Chm II: Calculate the mass of MgCO3 formed when 18.4 g of MgBr2 is combined with a solution containing excess K2CO3.
Chm II: Calculate the volume at STP of CO2 formed when 16 Chm II: Calculate the volume at STP of CO2 formed when 16.8 g of MgCO3 is decomposed creating CO2 & MgO.
Limiting Reactant The reactant that gets used up The reactant that determines the amount of product formed
Excess Reactant The reactant that does not get used up
Stoichiometry with Multiple Reagents Perform same steps for all reactants Choose least amount of product
Calculate the mass of glucose (C6H12O6) formed when 880 g of carbon dioxide is combined with 720 g of water in photosynthesis
Chm II: Calculate the mass of BaSO4 formed when 104 g of BaCl2 is combined with 250 mL 1.00 M(mole/L) K2SO4
Calculate the mass of solid formed when 104 g of BaCl2 is combined with 250 mL 1.00 M K2SO4
Calculate the mass of solid formed when 26 Calculate the mass of solid formed when 26.1 g of Ba(NO3)2 is combined with 120 mL 1.00 M K2SO4
Drill: Calculate the # of molecules of NH3 formed when of 4 Drill: Calculate the # of molecules of NH3 formed when of 4.0 mg of H2 react with 1.12 mL of N2 gas at STP.
Theoretical Yield The amount determined through stoichiometry The amount solved for on paper
Experimental Yield The amount obtained in the lab Actual yield
Percent yield % Yield = (Exp/Theo) x 100 %
68 g NH3 was obtained in lab when 140 g of N2 reacts with excess H2 68 g NH3 was obtained in lab when 140 g of N2 reacts with excess H2. Calculate percent yield.
510 g PH3 was obtained when 0. 62 kg of P4 reacts with excess H2 510 g PH3 was obtained when 0.62 kg of P4 reacts with excess H2. Calculate percent yield.
Chm II Drill Problem: 41 Page 115
Determine the volume of O2 released at STP when 32 kg of Fe2O3 is purified with an 80.0 % yield making Fe & O2
Calculate the volume of oxygen gas at STP required to burn 12 kg of erythrose (C4H8O4)
Drill: Determine the molecules of PH3 formed at STP when 1 Drill: Determine the molecules of PH3 formed at STP when 1.24 g P4 reacts with 672 mL of H2:
Calculate the mass of BaSO4 formed when 41 Calculate the mass of BaSO4 formed when 41.6 g of barium chloride is added to 250 ml of 0.40 M potassium sulfate giving a 50.0 % yield:
Calculate the mass of CaSO4 formed when 2 Calculate the mass of CaSO4 formed when 2.00 g of calcium bromide is added to 75 mL of 0.40 M sodium sulfate:
Chm II Homework Problem: 105 Page 120
Chm II Test on Wednesday
Determine the volume of CO2 formed at STP when 1 Determine the volume of CO2 formed at STP when 1.62 g Ca(HCO3)2 is decomposed forming CaO, CO2, & H2O:
3. 67 g of lead(II)bromide was obtained when 33 3.67 g of lead(II)bromide was obtained when 33.1 g of lead(II)nitrate was added to 1500 mL 0.10 M potassium bromide. Calculate the % yield & the molarity of all ions remaining in the solution.
Drill: 3.67 g of PbBr2 was obtained when 33.1 g of Pb(NO3)2 was added to 1500 mL of 0.10 M NaBr. Calculate the % yield.
Calculate the volume of oxygen gas at STP required to burn 50 Calculate the volume of oxygen gas at STP required to burn 50.0 mg C5H8O2:
Calculate the volume of gaseous product formed when 2 Calculate the volume of gaseous product formed when 2.24 L of F2 is bubbled through a 375 mL solution 0.20 M KCl:
Calculate the volume in mL of gaseous products formed at STP when 6 Calculate the volume in mL of gaseous products formed at STP when 6.0 mg of C2H6 is burned in excess oxygen:
33. 1 g of Pb(NO3)2 was added to 1500 mL 0. 10 M KI 33.1 g of Pb(NO3)2 was added to 1500 mL 0.10 M KI. Calculate mass of PbI2 formed.
Calculate the volume of gaseous product formed when 4 Calculate the volume of gaseous product formed when 4.2 kg of MgCO3 is heated with a 75 % yield:
Calculate the mass of liquid product formed when 6 Calculate the mass of liquid product formed when 6.0 g of sodium hydroxide is added to a 250 mL solution 0.40 M hydrochloric acid:
33. 1 g of lead(II)nitrate was added to 1500 mL 0 33.1 g of lead(II)nitrate was added to 1500 mL 0.10 M potassium iodide. Calculate mass of solid product formed.
An 30.0 g unknown sample (containing only C, H, & O) was burned in excess oxygen yielding 66 g CO2 & 36 g H2O. Calculate its empirical formula :
An 240 g unknown sample (containing only C, H, S, & O) was burned in excess oxygen yielding 352 g CO2, 144 g H2O, & 128 g, SO2. Calculate its empirical formula :
Calculate the mass of solid product formed when 3 Calculate the mass of solid product formed when 3.31 g of Pb(NO3)2 is added to a 75.0 mL solution 0.20 M KI:
Drill Convert 66.2 mg lead(II)nitrate to atoms
Drill 20.0 g of solid sodium hydroxide is added to 800.0 mL of 0.50 M hydrochloric acid. Calculate volume of water formed.
Name the Following: BaCl2 Mn2O3 SF2 NH3 CaSO4 (NH4)3PO3 Fe(NO3)2 KClO3
Derive formulas for Sodium hydroxide Calcium carbonate Iron(III)phosphate Dinitrogen tetroxide
64 kg SO2 to mL gas 11.2 mL NH3 to atoms 180 km/hr to cm/s Make conversions: 64 kg SO2 to mL gas 11.2 mL NH3 to atoms 180 km/hr to cm/s
7. 2 g Ca(HCO3)2 was synthesized when 7. 0 g of CaO, 2 7.2 g Ca(HCO3)2 was synthesized when 7.0 g of CaO, 2.24 L of CO2 at STP, & 9.0 g H2O are combined. Calculate % yield.
Predict all for: Aqueous iron(III)chloride and aqueous lead(II)nitrate are combined
Predict all for: Fluorine gas is bubbled through aqueous aluminum chloride
Predict all for: Ethane (C2H6) is burned in excess oxygen
Predict all for: Solid barium hydroxide is added to a solution of hydroiodic acid