CHEM 12
Stoichiometry Review
Stoichiometry II
9/30/2015
Name: _______________________________
1. (a) Define the terms limiting reactant and excess reactant.
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(b) Why are the amounts of products formed in a reaction determined only by the amount of
the limiting reactant?
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(c) Why should you base your choice of what compound is the limiting reactant on its number
of moles, not its initial mass in grams?
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2. A bottling plant has 121 515 bottles with a capacity of 355ml, 122 500 caps, and 40 875L of
beverage.
(a) How many bottles can be filled and capped?
(b) How much of each item is left over?
(c) Which component limits the production?
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CHEM 12
Stoichiometry Review
9/30/2015
3. Sodium hydroxide reacts with carbon dioxide as follows:
2NaOH(s) + CO2(g) → Na2CO3(s) + H2O(l)
(a) Which reagent is the limiting reactant when 1.85mol NaOH and 1.00 mol CO2 are allowed
to react?
(b) How many moles of Na2CO3 can be produced?
(c) How many moles of the excess reactant remain after the completion of the reaction?
4. Aluminum hydroxide reacts with sulfuric acid as follows:
2Al(OH)3(s) + 3H2SO4(aq) → Al2(SO4)3 (aq)+ 6 H2O(l)
(a) Which reagent is the limiting reactant when 0.500mol Al(OH)3 and 0.500mol H2SO4 are
allowed to react?
(b) How many moles of Al2(SO4)3 can form under these conditions?
(c) How many moles of excess reactant remain after the completion of the reaction?
CHEM 12
Stoichiometry Review
9/30/2015
5. When benzene (C6H6) reacts with bromine (Br2), bromobenzene (C6H5Br) is obtained:
C6H6 + Br2 → C6H5Br + HBr
(a) What is the theoretical yield of bromobenzene in this reaction when 30.0g of benzene reacts
with 65.0g of bromine?
(b) If the actual yield of bromobenzene was 42.3g, what was the percent yield?
 Actual yield (g) 
 100
% yield  
 Theoretica l yield (g) 
6. Solutions of sulfuric acid, H2SO4, and lead(II) acetate (Pb(CH3COO)2) react to form solid
lead (II) sulfate (PbSO4) and a solution of acetic acid (CH3COOH).
(a) Write the balanced equation for the above reaction:
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(b) If 7.50g of sulfuric acid and 7.50g of lead(II) acetate are mixed, calculate the number of
grams of sulfuric acid, lead(II) acetate, lead(II) sulfate, and acetic acid present in the mixture
after the reaction is complete
CHEM 12
Stoichiometry Review
9/30/2015
7. When ethane (C2H6) reacts with chlorine gas (Cl2), the main product is chloroethane, C2H5Cl;
but other products can be produced containing chlorine such as C2H4Cl2. The formation of
these unwanted products reduces the yield of C2H5Cl. Given the skeleton (unbalanced)
reaction is:
___C2H6(g) + ___Cl2(g) → ___C2H5Cl(g) + ___HCl
(a) Calculate the theoretical yield of C2H5Cl when 125g of ethane and 255g of Cl2, assuming
that C2H6 and Cl2 react only as shown in the above reaction.
(b) Calculate the percent yield of C2H5Cl if the reaction produces 206g of C2H5Cl
8. The koala dines exclusively on eucalyptus leaves. Its digestive system detoxifies the
eucalyptus oil, a poison to other animals. The chief constituent in eucalyptus oil is a chemical
called eucalyptol, which contains 77.87% C, 11.76% H and 10.37% O.
(a) What is the empirical formula for this substance?
(b) What is the molecular formula for this substance given a FW = 154 g/mol?
9. A mixture of N2(g) and H2(g) reacts in a closed container to form ammonia, NH3(g). The reaction ceases before either reactant has been totally consumed. At this stage 3.0 mol of nitrogen.
3.0 mol of hydrogen, and 3.0mol of ammonia are present. How many moles of each nitrogen
and hydrogen were present initially? (You will need to write a balanced equation of this reaction from the work equation above)