Physical Science Name ______
Chapter 6: Types & Balancing Date _____/_____/_____ Period ______
Chemical Reactions Worksheet I
1. A decomposition reaction starts with one reactant and ends up with two or more products. Which of
the following reactions are decomposition reactions? Circle the letter or letters and balance the circled reaction(s).
a. 2 NaCl ® 2 Na + ____ Cl2
b. ____ Na + ____ Cl2 ® ____ NaCl
c. 2 H2O ® 2 H2 + ____ O2
d. ____ H2 + ____ O2 ® ____ H2O
e. ____ NaOH + ____ HCl ® ____ HOH + ____ NaCl
2. A synthesis reaction starts with two reactants and ends up with one product. Which of the following
reactions are synthesis reactions? Circle the letter or letters and balance the circled reaction(s).
a. ____ NaCl ® ____ Na + ____ Cl2
b. ____ Na + ____ HCl ® ____ H2 + ____ NaCl
c. 2 H2 + ____ O2 ® 2 H2O
d. ____ NaOH + ____ HCl ® ____ HOH + ____ NaCl
e. 2 K + ____ Cl2 ® 2 KCl
3. A single replacement reaction starts with a compound and an element and ends up with a “new” or
different compound and “new” or different element as the products. The uncombined element takes
the place of the combined element in the compound. Which of the following reactions are single
replacement reactions? Circle the letter or letters and balance the circled reaction(s).
a. ____ NaCl ® ____ Na + ____ Cl2
b. ____ NaOH + ____ HCl ® ____ HOH + ____ NaCl
c. ____ K + ____ AgCl ® ____ Ag + ____ KCl
d. ____ Ca + ____ S ® ____ CaS
e. 2 Na + 2 HCl ® ____ H2 + 2 NaCl
4. A double replacement reaction starts with two compounds and ends with two “new” or different
compounds as the products. The elements that make up each of the two compounds simple change
partners to produce the two new compounds. Which of the following reactants are double
replacement reactions? Circle the letter or letters and balance the circled reaction(s).
a. ____ NaCl ® ____ Na + ____ Cl2
b. ____ Na2CO3 + ____ CaCl2 ® ____ CaCO3 + 2 NaCl
c. ____ Na + ____ HCl ® ____ H2 + ____ NaCl
d. 2 AgNO3 + ____ ZnCl2 ® 2 AgCl + ____ Zn(NO3) 2
e. ____ Ca + ____ S ® ____ CaS
Identifying and Balancing Chemical Equations
Identify each of the following equations below as synthesis (S), decomposition (D), single replacement (SR), double replacement (DR), neutralization (N), or combustion (C).
Type Balance
D 1. 2 HgO ® 2 Hg + ____ O2
DR 2. ____ NaCl + ____ AgNO3 ® ____ NaNO3 + ____ AgCl
SR 3. Mg + 2 HCl ® ____ MgCl2 + ____ H2
SR 4. ____ Zn + ____ H2SO4 ® ____ ZnSO4 + ____ H2
N 5. ____ NaOH + ____ HCl ® ____ NaCl + ____ HOH
DR 6. ____ Al2(SO4)3 + 3 Ca(OH)2 ® 2 Al(OH)3 + 3 CaSO4
S 7. 2 H2 + ____ O2 ® 2 H2O
SR 8. ____ Cl2 + 2 NaBr ® 2 NaCl + ____ Br2
SR 9. ____ Zn + ____ CuSO4 ® ____ ZnSO4 + ____ Cu
D 10. 2 KClO3 ® 2 KCl + 3 O2
SR 11. 3 H2O + 2 Fe ® ____ Fe2O3 + 3 H2
N 12. ____ Ca(OH)2 + 2 HNO3 ® ____ Ca(NO3)2 + 2 HOH
S 13. ____ Na2O + ____ CO2 ® ____ Na2CO3
S 14. 3 H2 + ____ N2 ® 2 NH3
SR 15. 2 HgO + ____ Cl2 ® 2 HgCl + ____ O2
S 16. 2 Na + ____ Br2 ® 2 NaBr
DR 17. ____ FeSO4 + ____ (NH4)2S ® ____ FeS + ____ (NH4)2SO4
C 18. 2 C2H6 + 7 O2 ® 4 CO2 + 6 H2O
D 19. 2 Al2O3 ® 4 Al + 3 O2
DR 20. ____ CuCl2 + ____ H2S ® ____ CuS + 2 HCl
N 21. 3 KOH + ____ H3PO4 ® 3 HOH + ____ K3PO4
N 22. ____ Mg(OH)2 + ____ H2SO4 ® ____ MgSO4 + 2 HOH
C 23. 2 C4H10 + 13 O2 ® 8 CO2 + 10 H2O
S 24. ____ S8 + 24 F2 ® 8 SF6
D 25. ____ NH4NO3 ® ____ N2O + 2 H2O