1405 Practice Questions
Chapter 7 – Chemical reactions
1. Which of the following represents a balanced chemical equation?
a. 2HCl + NaOH  H2O + NaCl
b. C2H2 + O2  2CO2 + H2O
c. Na + H2O  NaOH + H2
d. 6CO2 + 6 H2O  C6H12O6 + 6O2
2. The reaction for photosynthesis is: 6CO2 + 6H2O  C6H12O6 + 6O2
How many oxygen molecules (O2) are produced in the chemical reaction above?
a. 1
b. 2
c. 6
d. 12
3. Which of the following is a true statement?
a. Matter is conserved in a chemical reaction
b. Matter is created in a chemical reaction
c. Matter is destroyed in a chemical reaction
d. All of the above statements can be true depending on the reaction
4. Which of the following equations is balanced?
a. H2SO4 + 2NaOH  Na2SO4 + H2O
b. CH4 + Cl2  CH2Cl2 + HCl
c. H2O + MgO  Mg(OH)2
d. Al(OH)3 + H3PO4  AlPO4 + 2H2O
5. ___AlCl3 + ___Ba(OH)2  ___Al(OH)3 + ___BaCl2
When this equation is correctly balanced, the coefficient of the AlCl3 will be…
a. 1
b. 2
c. 4
d. 6
6. ___H2O  ___ H2 + ___O2
The coefficients of the correctly balanced equation for the reaction illustrated above are…
a. 1,1,1
b. 1,1,2
c. 2,1,2
d. 2,2,1
7. A balanced chemical equation has equal numbers of atoms of each type on both sided of the
equation. This illustrates the example of….
a. Conservation of energy
b. Conservation of mass
c. Action and reaction
d. Natural selection
8. In chemistry class, Mr. Smoak adds a small piece of sodium metal to a glass of water. The
sodium reacts violently with the water producing a small flame. The end products are hydrogen
gas and sodium hydroxide. Which of the following is the correct balanced chemical equation for
the reaction described above?
a. 2Na + 2H2O  2NaOH + H2
b. Na + H2O + O2  3NaOH + H2
c. H2O2 + 2 Na  2NaOH + H2
d. 2NaOH + H2  2Na + 2H2O
9. When 127 g of copper reacts with 32 g of oxygen gas to form copper (II) oxide, no copper or
oxygen is left over. How much copper (II) oxide is produced?
a. 32 g
b. 95 g
2Cu + O2  2CuO
c. 127 g
d. 159 g
10. In writing a chemical equation that produces hydrogen gas, the correct representation of hydrogen
gas is ____.
a. . H.
b. 2H.
c. H2.
d. OH.
Use the picture above
11. According to the law of conservation of mass, how much zinc was present in the zinc carbonate?
a. 40 g
b. 88 g
c. 104 g
d. 256 g
12. Which of the following reactions is an example of a single-replacement reaction?
a. 2AgNO3 + Cu  Cu(NO3)2 + 2Ag
b. NaOH + HCl  NaCl + H2O
c. CO2  C + O2
d. 4Fe(OH)2 + O2  4Fe(OH)3
13. Which of the following reactions is a decomposition reaction?
a. S8 + 8O2  8SO2
b. O2 + 2H2O  2H2O2
c. 2KClO3  2KCl + 3O2
d. 2Na + 2AgCl  2NaCl + 2Ag
14. Which is an example of a synthesis reaction?
a. HCl + KOH  KCl + H2O
b. Pb(NO3)2 + 2HBr  PbBr2 + 2HNO3
c. C + O2  CO2
d. Mg + H2SO4  MgSO4+ H2
15. What type of reaction does this illustration represent?
a. Synthesis
b. Decomposition
c. Single Replacement
d. Double Replacement
16. The following reaction is an example of __________?
C2H6 + O2  CO2 + H2O
a. Double replacement
b. Single replacement
c. Combustion
d. Synthesis
17. Choose the correct classification and set of coefficients considering the following reaction:
__KI + __PbCrO4  __K2CrO4 + __ PbI2
a. 2,1,1,1 and single replacement
b. 2,1,1,1 and double replacement
c. 1,1,2,1 and double replacement
d. 1,1,2,1 and single replacement
18. Iron (III) chloride + Sodium carbonate  Iron (III) carbonate + Sodium chloride
Which of these is the balanced equation for the reaction described above?
a. FeCl3 + Na2CO3  Fe2(CO3)3 + NaCl
b. 2FeCl3 + 3Na2CO3  Fe2(CO3)3 + 6NaCl
c. 2FeCl3 + 2Na2CO3 + 3Fe2(CO3)3 + 3NaCl
d. 3FeCl3 + 2Na2CO3  3Fe2(CO3)3 + 6NaCl
19. Which coefficients correctly balance the formula equation
NH4NO2 → N2 + H2O?
a. 1, 2, 2
b. 1, 1, 2
c. 2, 1, 1
20. What are the missing coefficients for the skeleton equation below?
Al2 (SO4)3 +
KOH → Al(OH)3
K2SO4
a. 1, 3, 2, 3 b. 2, 12, 4, 6
c. 4, 6, 2, 3
d. 1,6, 2,3
d. 2, 2, 2
1405 Practice Questions- answers
Chapter 7 – Chemical reactions
1. D
2. C
3. A
4. C
5. B
6. D
7. B
8. A
9. D
10. C
11. C
12. A
13. C
14. C
15. B
16. C
17. B
18. B
19. B
20. d
Balance and write a balanced equation, ionic equation& net ionic equation the following
reactions.
1. The reaction between sodium carbonate and silver nitrate: