Reactions Review Answer Key
Balancing the following reactions:
1. Zn(s) + 2HCl(aq)  ZnCl2(aq) + H2(g)
2. 2NO2(g)  N2O4(g)
3. ZnCl2+ 2AgNO3(aq)  2AgCl(aq) + Zn(NO3)2(aq)
4. 2KClO3(aq)  2KCl(aq) + 3O2(g)
5. MgCl2(aq) + 2HgNO3(aq)  2HgCl(s) + Mg(NO3)2(aq)
Write the balanced chemical equation for each reaction described below.
6. Gaseous hydrogen reacts with gaseous oxygen to form water.
2H2(g) + O2(g)  2H2O(l)
7. Iron metal forms iron (III) oxide in air.
4Fe(s) + 3O2(g)  2Fe2O3(s)
8. A precipitate forms when an aqueous solution of silver(I) nitrate is mixed with
hydrochloric acid (HCl) to make silver chloride and aqueous nitric acid (HNO3).
AgNO3(aq) + HCl(aq)  AgCl(s) + HNO3(aq)
9. Aluminum reacts with oxygen gas to form aluminum oxide.
4Al(s) + 3O2(g)  2Al2O3(s)
Identify the types of reactions below:
Types of reactions are:
-synthesis
-decomposition
-single replacement
double displacement
-combustion
7. 4C5H9O(g) + 27O2(g)  20CO2(g) + 18H2O(l) combustion
8. 2NaBr(aq) + Ca(OH)2(aq)  CaBr2(aq) + 2NaOH(aq) double displacement
9. 3Pb(s) + 2H3PO4(aq)  3H2(g) + Pb3(PO4)2(s) single replacement
10. Ag2O(s)  Ag(s) + O2(g) decomposition
11. 2NH3(g) + H2SO4(aq)  (NH4)2SO4(aq) synthesis
For the double displacement reactions below, predict the products that will form,
balance the equations, and identify the precipitate that form.
12. CuBr2(aq) + Na2CO3(aq)  CuCO3(s) + 2NaBr(aq)
13. Na2SO4(aq) + Ca(NO3)2(aq)  2NaNO3(aq) + CaSO4(s)
Write the ionic and net ionic equations for the reaction below.
14. 2Na3PO4(aq) + 3PbBr2(aq)  6NaBr(aq) + Pb3(PO4)2(s)
Ionic:
6Na+(aq) + 2PO43-(aq) + 3Pb2+(aq) + 6Br-(aq)  6Na+(aq) +6Br-(aq) + Pb3(PO4)2(s)
Net Ionic:
3Pb2+(aq) + 2PO43-(aq)  Pb3(PO4)2(s)
Chemical Reactions Review
Balancing the following reactions:
1. Zn(s) + HCl(aq)  ZnCl2(aq) + H2(g)
2. NO2(g)  N2O4(g)
3. ZnCl2+ AgNO3(aq)  AgCl(aq) + Zn(NO3)2(aq)
4. KClO3(aq)  KCl(aq) + O2(g)
5. MgCl2(aq) + HgNO3(aq)  HgCl(s) + Mg(NO3)2(aq)
Write the balanced chemical equation for each reaction described below.
6. Gaseous hydrogen reacts with gaseous oxygen to form water.
7. Iron metal forms iron (III) oxide in air.
8. A precipitate forms when an aqueous solution of silver(I) nitrate is mixed with
hydrochloric acid (HCl) to make silver chloride and aqueous nitric acid (HNO3).
9. Aluminum reacts with oxygen gas to form aluminum oxide.
Identify the types of reactions below:
Types of reactions are:
-synthesis
-decomposition
-single replacement
double displacement
-combustion
7. 4C5H9O(g) + 27O2(g)  20CO2(g) + 18H2O(l)
8. 2NaBr(aq) + Ca(OH)2(aq)  CaBr2(aq) + 2NaOH(aq)
9. 3Pb(s) + 2H3PO4(aq)  3H2(g) + Pb3(PO4)2(s)
10. Ag2O(s)  Ag(s) + O2(g)
11. 2NH3(g) + H2SO4(aq)  (NH4)2SO4(aq)
For the double displacement reactions below, predict the products that will form,
balance the equations, and identify the precipitate that form.
12. CuBr2(aq) + Na2CO3(aq) 
13. Na2SO4(aq) + Ca(NO3)2(aq) 
Write the ionic and net ionic equations for the reaction below.
14. 2Na3PO4(aq) + 3PbBr2(aq)  6NaBr(aq) + Pb3(PO4)2(s)
Ionic:
Net Ionic: