Drill: CaCl 2 + F 2  CaCl 2 + Na  CaCl 2 + KNO 3  CaCl 2 + K 2 SO 4 

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 NH 3 formed at STP when 6.0 kg of H 2 react with excess N 2 to form NH 3

Drill: Calculate the number of molecules of oxygen gas required to burn 3.0 ng of C 5 H 10 O 5

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 MgCO 3 formed when 18.4 g of MgBr 2 is combined with a solution containing excess K 2 CO 3.

Chm II: Calculate the volume at STP of CO 2 formed when 16.8 g of MgCO 3 is decomposed creating CO 2 & 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 (C 6 H 12 O 6 ) formed when 880 g of carbon dioxide is combined with 720 g of water in photosynthesis

Chm II: Calculate the mass of BaSO 4 formed when 104 g of BaCl 2 is combined with 250 mL 1.00 M(mole/L) K 2 SO 4

Calculate the mass of solid formed when 104 g of BaCl 2 is combined with 250 mL 1.00 M K 2 SO 4

Calculate the mass of BaSO 4 formed when 26.1 g of Ba(NO 3 ) 2 is combined with 120 mL 1.00 M K 2 SO 4

Drill: Calculate the # of molecules of NH 3 formed when of 4.0  g of H 2 react with 1.12 mL of N 2 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 NH 3 was obtained in lab when 140 g of N 2 reacts with excess H 2. Calculate percent yield.

510 g PH 3 was obtained when 0.62 kg of P 4 reacts with excess H 2. Calculate percent yield.

Chm II Drill Problem: 41 Page 115

Determine the volume of O 2 released at STP when 32 kg of Fe 2 O 3 is purified with an 80.0 % yield making Fe & O 2

Calculate the volume of oxygen gas at STP required to burn 12 kg of erythrose (C 4 H 8 O 4 )

Drill: Determine the molecules of PH 3 formed at STP when 1.24 g P 4 reacts with 672 mL of H 2 :

Calculate the mass of BaSO 4 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 CaSO 4 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 CO 2 formed at STP when 1.62 g Ca(HCO 3 ) 2 is decomposed forming CaO, CO 2, & H 2 O:

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 PbBr 2 was obtained when 33.1 g of Pb(NO 3 ) 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 50.0 mg C 5 H 8 O 2 :

Calculate the volume of gaseous product formed when 2.24 L of F 2 is bubbled through a 375 mL solution 0.20 M KCl:

Calculate the volume in mL of gaseous products formed at STP when 6.0  g of C 2 H 6 is burned in excess oxygen:

33.1 g of Pb(NO 3 ) 2 was added to 1500 mL 0.10 M KI. Calculate mass of PbI 2 formed.

Calculate the volume of gaseous product formed when 4.2 kg of MgCO 3 is heated with a 75 % yield:

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 0.10 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 CO 2 & 36 g H 2 O. Calculate its empirical formula :

An 240 g unknown sample (containing only C, H, S, & O) was burned in excess oxygen yielding 352 g CO 2, 144 g H 2 O, & 128 g, SO 2. Calculate its empirical formula :

Calculate the mass of solid product formed when 3.31 g of Pb(NO 3 ) 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 mL of 0.50 M hydrochloric acid. Calculate volume of water formed.

Name the Following: BaCl 2 Mn 2 O 3 SF 2 NH 3 CaSO 4 (NH 4 ) 3 PO 3 Fe(NO 3 ) 2 KClO 3

Derive formulas for Sodium hydroxide Calcium carbonate Iron(III)phosphate Dinitrogen tetroxide

Make conversions: 64 kg SO 2 to mL gas 11.2  L NH 3 to atoms 180 km/hr to cm/s

7.2 g Ca(HCO 3 ) 2 was synthesized when 7.0 g of CaO, 2.24 L of CO 2 at STP, & 9.0 g H 2 O 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 (C 2 H 6 ) is burned in excess oxygen

Predict all for: Solid barium hydroxide is added to a solution of hydroiodic acid