CHM 111 Problem Solving Activity (100 points)
Name _________________________________
Balancing Chemical Equations
1. Balance the following chemical equations. (3 points each)
____CaC2 + ____H2O ____Ca(OH)2 + ____C2H2
____ C3H8O3 + ____O2 ____CO2 + ____H2O
____NaN3 ____Na + ____N2
___Al + ___N2 ___Al2N3
____Al(NO3)3 + ___NaOH ___Al(OH)3 + ___NaNO3
2. Write balanced equations for the following chemical reactions. (3 points each)
a. Calcium hydroxide reacts with hydrochloric acid to form calcium chloride and water.
. Hydrosulfuric acid reacts with iron (III) hydroxide to form solid iron (III) sulfide and water.
c. Sodium hydroxide reacts with copper (II) nitrate to form copper (II) hydroxide and sodium nitrate.
Stoichiometry
3. (a) When NaHCO3 is heated above 270, it decomposes to form sodium ca
onate, water, and ca
on dioxide. Write a balanced equation for the decomposition reaction of NaHCO3.
(2 points)
(a) Calculate the mass of Na2CO3 produced from the decomposition of 30.0g of NaHCO3.
(5 points)
4. A student reacts methane gas (CH4) with oxygen gas (O2).
(a) Write a balanced chemical equation for the reaction. (2 points)
(b) Calculate the theoretical yield of H2O if 8.0g of CH4 reacts with excess oxygen gas. (5 points)
(c) What is the percent yield? (2 points)
5. The manufacture of aluminum includes the production of cryolite (Na3AlF6) from the following reaction:
(a) What mass of HF(g) is required to make 185g of Na3AlF6? (5 points)
(b) How many liters of HF(g) are needed to produce 36.0g of Al2O3? The density of HF (g) at 25 is 1.15g/L. (5 points)
Limiting Reagents
6. Potassium superoxide, KO2, reacts with ca
on dioxide to form potassium ca
onate and oxygen. This reaction makes potassium superoxide useful in a self-contained
eathing apparatus.
(a) What mass of O2 is produced from the reaction of 6.00g of KO2 with 7.00g of CO2? (8 points)
(b) What mass of the excess reagent is left after the reaction? (5 points)
7. Sodium metal reacts with oxygen gas to produce the compound sodium oxide.
(a) Write a balanced equation for the reaction. (2 points)
(b) How much product, in grams, is produced when 3.0g of sodium reacts with 5.0g of oxygen gas? (8 points)
(c) How much of the excess reagent is left after the reaction is complete? (5 points)
8. Sulfur trioxide dissolves in water to make sulfuric acid, H2SO4.
(a) Write a balanced chemical equation for the reaction. (2 points)
(b) Calculate the mass of sulfuric acid that could be produced from the reaction of 10.0 mL of water (d=1.00g/mL) and 20.0 g of SO3? (8 points)
Solution Stoichiometry
9. What mass of Cu(OH)2 is produced from the reaction of 50.0mL of 3.00MNaOH with excess Cu(NO3)2? (6 points)
Cu(NO3)2 + 2NaOH Cu(OH)2 + 2NaNO3
10. What volume of 1.50M Ca(OH)2 is needed to react with 25.0mL of 2.0M HCl solution?
(6 points)
Ca(OH)2 + 2HCl 2H2O + CaCl2
CHM 111 Problem Solving Activity (100 points)
Name _________________________________
Balancing Chemical Equations
1. Balance the following chemical equations. (3 points each)
____CaC2 + ____H2O ____Ca(OH)2 + ____C2H2
____ C3H8O3 + ____O2 ____CO2 + ____H2O
____NaN3 ____Na + ____N2
___Al + ___N2 ___Al2N3
____Al(NO3)3 + ___NaOH ___Al(OH)3 + ___NaNO3
2. Write balanced equations for the following chemical reactions. (3 points each)
a. Calcium hydroxide reacts with hydrochloric acid to form calcium chloride and water.
. Hydrosulfuric acid reacts with iron (III) hydroxide to form solid iron (III) sulfide and water.
c. Sodium hydroxide reacts with copper (II) nitrate to form copper (II) hydroxide and sodium nitrate.
Stoichiometry
3. (a) When NaHCO3 is heated above 270, it decomposes to form sodium ca
onate, water, and ca
on dioxide. Write a balanced equation for the decomposition reaction of NaHCO3.
(2 points)
(a) Calculate the mass of Na2CO3 produced from the decomposition of 30.0g of NaHCO3.
(5 points)
4. A student reacts methane gas (CH4) with oxygen gas (O2).
(a) Write a balanced chemical equation for the reaction. (2 points)
(b) Calculate the theoretical yield of H2O if 8.0g of CH4 reacts with excess oxygen gas. (5 points)
(c) What is the percent yield? (2 points)
5. The manufacture of aluminum includes the production of cryolite (Na3AlF6) from the following reaction:
(a) What mass of HF(g) is required to make 185g of Na3AlF6? (5 points)
(b) How many liters of HF(g) are needed to produce 36.0g of Al2O3? The density of HF (g) at 25 is 1.15g/L. (5 points)
Limiting Reagents
6. Potassium superoxide, KO2, reacts with ca
on dioxide to form potassium ca
onate and oxygen. This reaction makes potassium superoxide useful in a self-contained
eathing apparatus.
(a) What mass of O2 is produced from the reaction of 6.00g of KO2 with 7.00g of CO2? (8 points)
(b) What mass of the excess reagent is left after the reaction? (5 points)
7. Sodium metal reacts with oxygen gas to produce the compound sodium oxide.
(a) Write a balanced equation for the reaction. (2 points)
(b) How much product, in grams, is produced when 3.0g of sodium reacts with 5.0g of oxygen gas? (8 points)
(c) How much of the excess reagent is left after the reaction is complete? (5 points)
8. Sulfur trioxide dissolves in water to make sulfuric acid, H2SO4.
(a) Write a balanced chemical equation for the reaction. (2 points)
(b) Calculate the mass of sulfuric acid that could be produced from the reaction of 10.0 mL of water (d=1.00g/mL) and 20.0 g of SO3? (8 points)
Solution Stoichiometry
9. What mass of Cu(OH)2 is produced from the reaction of 50.0mL of 3.00MNaOH with excess Cu(NO3)2? (6 points)
Cu(NO3)2 + 2NaOH Cu(OH)2 + 2NaNO3
10. What volume of 1.50M Ca(OH)2 is needed to react with 25.0mL of 2.0M HCl solution?
(6 points)
Ca(OH)2 + 2HCl 2H2O + CaCl2