Drill:•CaCl2 + F2

•CaCl2 + Na

•CaCl2 + KNO3

•CaCl2 + K2SO4

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 6.0 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 66.2 g of

lead (II)nitrate is combined with excess

potassium iodide

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 16.8 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 BaSO4 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 whenof 4.0 g 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. Calculate percent yield.

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 1.24 g P4 reacts with

672 mL of H2:

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

2.00 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 1.62 g Ca(HCO3)2 is

decomposed forming CaO, CO2, & H2O:

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 50.0 mg

C5H8O2:

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 6.0 g of

C2H6 is burned in excess oxygen:

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 4.2 kg of MgCO3 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 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 3.31 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

Make conversions:

•64 kg SO2 to mL gas

•11.2 L NH3 to atoms

•180 km/hr to cm/s

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