Unit 6: Stoichiometry Review
1.How many moles of hydrogen are required to react with 2.5 moles of oxygen to produce water?
2 H2 + O2  2 H2O
2. How many moles of hydrochloric acid, HCl, will be required to produce 0.40 moles of hydrogen gas
by reaction with zinc? The equation is:
Zn + 2 HCl  ZnCl2 + H2
3. Hydrogen and nitrogen react to form ammonia (NH3). How many moles of hydrogen will be
required to produce 1.70 moles of ammonia, NH3?
4. Consider the acid-base neutralization reaction between HCl and NaOH. How many moles of HCl are
required to completely neutralize 30.0 mL of 0.318 M NaOH?
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5. Carbon and oxygen react to produce carbon dioxide. How many grams of carbon will react with
0.25 moles of oxygen in this reaction?
6. How many litres of oxygen can be produced at STP when 15.6 g of sulphur trioxide, SO3 are
decomposed into sulphur (S) and oxygen gas?
7. Chlorine gas and solid carbon react to form carbon tetra chloride. How many grams of chlorine are
required to produce 355 g of carbon tetrachloride by reaction with carbon?
8. A tablet of Tums (CaCO3(s)) has a mass of 0.750 g. The concentration of HCl(aq) in the stomach is
about 0.25 M. What is the volume of stomach acid can a Tums tablet neutralize?
The equation for the reaction is:
2 HCl(aq) + CaCO3(s)  CaCl2(aq) + H2O(l)
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9. A solution containing 0.128 mol AgNO3 is mixed with a solution containing an excess
of aqueous sodium chloride. It is found that 17.8 g of AgCl(s) is formed. Calculate the
percent yield of silver chloride. The chemical reaction is as follows:
AgNO3(aq) + NaCl(aq)  AgCl(s) + NaNO3(aq)
10. When 5.44 g of copper are reacted with an excess of oxygen, 5.10 g of copper (II) oxide (CuO)
are formed. Calculate the percent yield of copper (II) oxide.
11. Assume that 12.0 g of oxygen are reacted with 20.0 g of magnesium to produce magnesium oxide, MgO.
Determine which reactant is the limiting reactant, calculate the number of grams of
product formed, and determine how many grams of the excess reagent are present after the reaction
has occurred.
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12. If 13.1 g of potassium are reacted with 18.0 g of oxygen to produce potassium oxide, K2O.
Determine which reactant is the limiting reactant, calculate the number of grams of
product formed, and determine how many grams of the excess reagent are present after the reaction
has occurred.
13. A solution of silver nitrate reacts with aluminum to produce silver and one other product.
The 0.400 mol/L silver nitrate solution has a volume of 8.0 L. The mass of aluminum placed in the
solution is 50.0 g.
a) calculate the theoretical yield of silver
b) if 305 g of silver is actually produced, calculate the % yield of silver.
14. Several 10.00 ml Sulphuric acid H2SO4 samples were titrated with a solution of 0.0890 M sodium
hydroxide. An average volume of 15.41 ml of sodium hydroxide was required to reach the endpoint.
Calculate the [H2SO4].
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