STOICHIOMETRY PRACTICE

BELLWORK #3 3/2/2011 Define the following terms: a) limiting reactant b) excess reactants c) Percent yield d) Theoretical yield e) Actual yield

STOICHIOMETRY PRACTICE Determine all possible mole ratios for the following balanced chemical equations: a)4Al(s) + 3O 2 (g)  2Al 2 O 3 (s) b) 3Fe(s) + 4H 2 O(l)  Fe 3 O 4 (s) + 4H 2 (g) c) 2HgO(s)  2Hg(l) + O 2 (g)

STOICHIOMETRY PRACTICE Balance the following equations and determine the possible mole ratios a)ZnO(s) + HCl(aq)  ZnCl 2 (aq) + H 2 O(l) b)butane (C 4 H 10 ) + oxygen  carbon dioxide + water

STOICHIOMETRY PRACTICE Determine the mass of sodium chloride produced when 1.25 moles of chlorine gas reacts vigorously with sodium. –STEP 1- WRITE THE EQUATION –STEP 2- BALANCE THE EQUATION –STEP 3- STATE GIVEN AND UNKNOWN –STEP 4- SOLVE

STOICHIOMETRY PRACTICE NH 4 NO 3 produces N 2 O gas and H 2 O when it decomposes. Determine the mass of water produced from the decomposition of 25.0 grams of solid ammonium nitrate. –STEP 1- WRITE THE EQUATION –STEP 2- BALANCE THE EQUATION –STEP 3- STATE GIVEN AND UNKNOWN –STEP 4- SOLVE

STOICHIOMETRY PRACTICE Chlorine is used by textile manufacturers to bleach cloth. Excess chlorine is destroyed by its reaction with sodium thiosulfate, Na 2 S 2 O 3 : Na 2 S 2 O 3 (aq) + 4Cl 2 (g) + 5H 2 O(aq)  2NaHSO 4 (aq) + 8HCl(aq) a. How many moles of Na 2 S 2 O 3 are needed to react with 0.12mol of Cl 2 ?

Percent Yield Practice Problems Write the problem down: 1.A student adds 200.0g of C 7 H 6 O 3 to an excess of C 4 H 6 O 3, this produces C 9 H 8 O 4 and C 2 H 4 O 2. Calculate the percent yield if 231 g of aspirin (C 9 H 8 O 4 ) is produced. C 7 H 6 O 3 + C 4 H 6 O 3  C 9 H 8 O 4 + C 2 H 4 O 2

Percent Yield Practice Problems 1.A student adds 200.0g of C 7 H 6 O 3 to an excess of C 4 H 6 O 3, this produces C 9 H 8 O 4 and C 2 H 4 O 2. Calculate the percent yield if 231 g of aspirin (C 9 H 8 O 4 ) is produced. C 7 H 6 O 3 + C 4 H 6 O 3  C 9 H 8 O 4 + C 2 H 4 O 2 ANSWER: ≈90%

Percent Yield Practice Problems 2. Quicklime, CaO, can be prepared by roasting limestone, CaCO 3, according to the chemical equation below. When 2.00 x 10 3 g of CaCO 3 are heated, the actual yield of CaO is 1.50 x 10 3 g. What is the percentage yield? CaCO 3  CaO + CO 2

Percent Yield Practice Problems 2. Quicklime, CaO, can be prepared by roasting limestone, CaCO 3, according to the chemical equation below. When 2.00 x 10 3 g of CaCO 3 are heated, the actual yield of CaO is 1.50 x 103 g. What is the percentage yield? CaCO 3  CaO + CO 2 ANSWER: ≈93.8%

Percent Yield Practice Problems 3.Aluminum reacts with an aqueous solution containing excess copper (II) sulfate. If 1.85 g Al reacts and the percentage yield of Cu is 56.6%, what mass of Cu is produced? Al + CuSO 4  Cu + Al 2 (SO 4 ) 3

Percent Yield Practice Problems 3.Aluminum reacts with an aqueous solution containing excess copper (II) sulfate. If 1.85 g Al reacts and the percentage yield of Cu is 56.6%, what mass of Cu is produced? Al + CuSO 4  Cu + Al 2 (SO 4 ) 3 ANSWER: 3.70g

1)Balance this equation and state which of the six types of reaction is taking place: __ Mg + __ HNO 3  __ Mg(NO 3 ) 2 + __H 2 Type of reaction: __________________________

2)If I start this reaction with 40 grams of magnesium and an excess of nitric acid, how many grams of hydrogen gas will I produce?

3)If 1.7 grams of hydrogen is actually produced, what was my percent yield of hydrogen?

4)Balance this equation and state what type of reaction is taking place: ____ NaHCO 3  ____ NaOH + ____ CO 2 Type of reaction: __________________________

5)If 25 grams of carbon dioxide gas is produced in this reaction, how many grams of sodium hydroxide should be produced?

6)If 50 grams of sodium hydroxide are actually produced, what was my percent yield?

CHEM BELLWORK #33/7/11 Given the following equation: CaCl 2 + Li 3 PO 4 ---> LiCl + Ca 3 (PO 4 ) 2 a) If you start with 82.4 g of CaCl 2 and you isolate 82.4 g of Ca 3 (PO 4 ) 2, what is your percent yield for this reaction?

If 80.0 g of sodium reacts with 72.0 g of iron (III) oxide, sodium acts as the limiting reactant.

The percent yield is the maximum amount of product that can be produced from a given amount of reactant.

How many moles of carbon dioxide is produced when 10.4 mol of propane gas is burned in excess oxygen? The equation for the combustion of propane is C 3 H 8 + O 2  CO 2 + H 2 O

Hydrofluoric acid reacts with HF 31.3g of silica to produce hexafluorosilicic acid. Determine the percent yield of H 2 SiF 6 if the actual yield is actual 60.3 g.