Stoich and % Yield Problems
1.
How many grams of chlorine gas are needed in the production of 200.0 grams of
bromine gas from sodium bromide?
Cl2 + 2NaBr ® 2NaCl + Br2
2.
Calculate the percent yield of a reaction that consumes 900.0 grams of
potassium chlorate in the preparation of 90.0 grams of oxygen?
2KClO3 ® 2KClO2 + O2
3.
In the reaction of 84.0 g of copper (II) oxide with hydrogen gas in a reaction
with a 92.4% yield, Determine the mass of copper produced?
CuO + H 2 ® Cu + H 2O
4.
How many grams of sodium hydroxide will react with 1.50 x 10-3 g of phosphoric
acid?
3NaOH + H 3PO4 ® 3H 2O + Na3PO4
5.
If 320.0 grams of sodium carbonate react with calcium hydroxide in a 74.67%
efficient reaction, how many grams of sodium hydroxide are formed?
Na2CO3 + Ca(OH )2 ® 2NaOH + CaCO3
6.
How many grams of sodium iodide are produced by the decomposition of 60.0 g
of sodium iodate if the reaction is 89.4% effective?
_ 2 _ NaIO3 ® _ 2 _ NaI + _ 3_O2
7.
If 10.0 g of aluminum sulfide are produced by the 94.2% effective reaction of
aluminum and sulfur, how many grams of sulfur were needed?
_ 2 _ Al + _ 3_ S ® ___ Al2 S3
8.
If 2.50 g of cupric sulfide is produced by decomposing cupric sulfate upon
heating, how many grams of cupric sulfate was necessary if the reaction is
90.00% efficient?
___CuSO4 ® ___ CuS + _ 2 _O2
9. 125.0 g of FeS react to form 167.3 g of FeCl2:
a. Determine the % yield of the reaction.
b. Calculate, based on that percent yield, the moles of H2S that will be
produced.
FeS(s) + 2HCl(aq) ® FeCl2(aq) + H 2S(g)
10. If 1.487 moles of lithium oxide react with water through a 79.4% effective reaction,
determine the mass of lithium hydroxide produced.
Li2O(s) + H 2O(l) ® 2LiOH(aq)
11. In order to produce 100.0 g of NaCl based on the following 84.3 % efficient reaction,
determine the moles of each reactant required.
Na 2SO4(aq) + CaCl2(aq) ® CaSO4(s) + 2NaCl(aq)
12. 0.941 moles of calcium hydroxide react to form 30.55 g of water. Determine the
percent yield of the reaction.
Ca(OH)2(aq) + 2HCl(aq) ® CaCl2(aq) + 2H 2O(l)
13. What mass of ethane must react in order to produce 4.73 moles of carbon dioxide if
the following reaction has a 91.8 % yield?
2C2H 6 + 7O 2 ® 4CO 2 + 6H 2O
14. 4.84 moles of oxygen react in the following 87.9 % yield reaction. Calculate the
mass of each product produced.
2Cu2S + 3O 2 ® 2Cu2O + 2SO2