Reactions Review
____ 1. All of the following are clues that a chemical reaction has taken place except
A. / a color changeB. / a solid forms
C. / the reactant is smaller
D. / a flame occurs
E. / bubbles form
____ 2. When the following equation is balanced with the smallest whole number coefficients, what is the coefficient for O2?
C3H8(g) + O2(g) --> CO2(g) + H2O(g)
A. / 4B. / 5
C. / 10
D. / 7
E. / None of the above
____ 3. When the equation
Cr2S3 + HCl --> CrCl3 + H2S
is balanced in standard form, one of the terms in the balanced equation is
A. / 3HClB. / 3H2S
C. / 2Cr2S3
D. / CrCl3
____ 4. The most common factors that cause chemical reactions to occur are all of the following except
A. / formation of a solidB. / formation of a gas
C. / formation of water
D. / a decrease in temperature
E. / transfer of electrons
____ 5. When an acid reacts with a base, which product always forms?
A. / hydrogen and carbon dioxideB. / water
C. / hydrogen
D. / carbon dioxide
E. / None of the above
____ 6. The reaction 2K(s) + Br2(l) --> 2KBr(s) is a(n) _____ reaction.
A. / double-displacementB. / precipitation
C. / oxidation-reduction
D. / single-replacement
E. / acid-base
____ 7. The reaction AgNO3(aq) + NaCl(aq) --> AgCl(s) + NaNO3(aq) is a(n) _____ reaction.
A. / none of theseB. / precipitation
C. / acid-base
D. / oxidation-reduction
E. / single-replacement
____ 8. The reaction HCl(aq) + KOH(aq) --> H2O(l) + KCl(aq) is a(n) _____ reaction.
A. / oxidation-reductionB. / precipitation
C. / single-replacement
D. / acid-base
E. / None of the above
____ 9. In what type of reaction is water always a product?
A. / decompositionB. / acid-base
C. / precipitation
D. / synthesis
E. / oxidation
____ 10. Classify the following reaction:
2Mg(s) + O2(g) --> 2MgO(s).
A. / combustionB. / synthesis
C. / oxidation-reduction
D. / two of these
E. / Oxidation-reduction, combustion, and synthesis are all correct.
____ 11. Classify the following reaction:
HNO3(aq) + KOH(aq) --> KNO3(aq) + H2O(l).
A. / combustionB. / precipitation
C. / acid-base
D. / oxidation-reduction
E. / two of these
____ 12. The equation
2Al(s) + 2Br3(l) --> 2AlBr3(s)
is a(n) _____ reaction.
A. / oxidation-reduction onlyB. / combustion
C. / oxidation-reduction and synthesis
D. / decomposition
E. / synthesis only
____ 13. A reaction that involves a transfer of electrons is called a(n) _____ reaction.
A. / acid-baseB. / oxidation-reduction
C. / double-displacement
D. / precipitation
E. / None of the above
____ 14. The equation
2Ag2O(s) --> 4Ag(s) + O2(g)
is a(n) _____ reaction.
A. / synthesisB. / combustion
C. / oxidation-reduction
D. / decomposition
E. / two of these
____ 15. The equation
CH4(g) + 2O2(g) --> CO2(g) + 2H2O(g)
is a(n) _____ reaction.
A. / decompositionB. / combustion
C. / oxidation-reduction
D. / synthesis
E. / two of these
16. Solid calcium carbide, CaC2, will react with water to produce acetylene gas, C2H2, and aqueous calcium hydroxide. Write the balanced equation for this reaction.
17. Balance the following equation for the reaction where hydrogen sulfide gas burns in oxygen gas to form gaseous water and sulfur dioxide gas.
H2S(g) + O2(g) --> SO2(g) + H2O(g)
18. Balance the equation
NaBH4 + BF3 --> NaBF4 + B2H6
19. Balance the equation
MgCl2 + K3PO4 --> Mg3(PO4)2 + KCl.
20. Balance the equation
C6H14 + O2 --> CO2 + H2O.
21. Balance the equation
As2O3(s) + Ca(OH)2(aq) --> Ca3(AsO4)2(s) + H2O(l).
22. Balance the equation
Mg(OH)2(aq) + HBr(aq) --> MgBr2(aq) + H2O(l).
23. Balance the equation
Sb(s) + O2(g) --> Sb2O3(s).
24. Balance the equation
Mg(s) + H3PO4(aq) --> Mg3(PO4)2(aq) + H2(g).
25. Balance the equation
KClO3(s) --> KCl(s) + O2(g).
26. Balance the equation
H2SO4(aq) + KOH(aq) --> K2SO4(aq) + H2O(l).
27. Balance the equation
Ba(OH)2(aq) + H3PO4(aq) --> Ba3(PO4)2(aq) + H2O(l).
28. Balance the equation
NaNO3(s) --> NaNO2(s) + O2(g).
29. Balance the equation
Al(s) + H2SO4(aq) --> Al2(SO4)3(aq) + H2(g).
30. Balance the equation
Mg(s) + O2(g) --> MgO(s).
31. Balance the equation
BaCl2(aq) + H2SO4(aq) --> BaSO4(s) + HCl(aq).
32. Balance the equation
Pb(NO3)2(aq) + K2CrO4(aq) --> PbCrO4(s) + KNO3(aq).
33. Balance the equation
(NH4)2Cr2O7(s) --> N2(g) + H2O(g) + Cr2O3(s).
34. Balance the equation for the reaction of calcium metal with oxygen gas to produce solid calcium oxide.
35. Balance the equation for the reaction of aluminum metal with solid iodine to form solid aluminum iodide.
36. Balance the equation for the reaction of potassium metal with water to form potassium hydroxide and hydrogen gas.
37. Balance the equation
Na(s) + H2O(l) --> H2(g) + NaOH(aq).
38. Balance the equation
Ca(s) + O2(g) --> CaO(s).
39. Balance the equation
Mg3N2(s) + H2O(l) --> NH3(g) + Mg(OH)2(s).
40. Balance the equation
CaCO3(s) + HCl(aq) --> H2O(l) + CO2(g) + CaCl2(aq).
41. Balance the equation
Fe(NO3)2(aq) + H2S(g) --> FeS(s) + HNO3(aq).
42. Balance the equation
C8H18(l) + O2(g) --> CO2(g) + H2O(g).
43. Balance the equation
K(s) + H2O(l) --> KOH(aq) + H2(g).
44. Balance the equation
NH3(g) + O2(g) --> NO(g) + H2O(l).
45. Balance the equation
Al(s) + S(s) --> Al2S3(s).
46. Balance the equation
Zn(s) + H3PO4(aq) --> Zn3(PO4)2(s) + H2(g).
47. Write the molecular equation, the complete ionic equation, and the net ionic equation for the following reaction: Aqueous solutions of copper(II) nitrate and sodium hydroxide are mixed to form solid copper(II) hydroxide and aqueous sodium nitrate.
48. Balance the molecular equation when aqueous potassium hydroxide reacts with aqueous sulfuric acid to yield water and aqueous potassium sulfate.
49. Balance the equation
HCl(aq) + Ca(OH)2(aq) --> CaCl2(aq) + H2O(l)