Chemistry worksheet featuring single and double replacement reaction problems with blank spaces for balancing equations.

Here are the balanced chemical equations for each reaction. I have predicted the products based on standard reaction rules (activity series for single replacement, solubility rules for double replacement) and balanced the atoms on both sides.

SINGLE REPLACEMENT

*Rule: A more active element replaces a less active one. If the element is less active, write "NR" (No Reaction).*

Example I: $2\text{Al}_{(s)} + 3\text{Pb(NO}_3)_{2(aq)} \rightarrow 3\text{Pb}_{(s)} + 2\text{Al(NO}_3)_{3(aq)}$
*(Aluminum is more active than Lead)*

Example II: $\text{Cl}_{2(g)} + \text{CuI}_{2(aq)} \rightarrow \text{CuCl}_{2(aq)} + \text{I}_{2(s)}$
*(Chlorine is more active than Iodine)*

Example III: $2\text{Ag}_{(s)} + \text{Ca(IO}_3)_{2(aq)} \rightarrow \text{NR}$
*(Silver is less active than Calcium, so no reaction occurs)*

1. $\text{Zn}_{(s)} + \text{CuSO}_{4(aq)} \rightarrow \text{ZnSO}_{4(aq)} + \text{Cu}_{(s)}$
*(Zinc replaces Copper)*

2. $\text{Cl}_{2(g)} + 2\text{KI}_{(aq)} \rightarrow 2\text{KCl}_{(aq)} + \text{I}_{2(s)}$
*(Chlorine replaces Iodine)*

3. $\text{Ni}_{(s)} + \text{MgSO}_{4(aq)} \rightarrow \text{NR}$
*(Nickel is less active than Magnesium)*

4. $\text{Br}_{2(aq)} + \text{CaCl}_{2(s)} \rightarrow \text{NR}$
*(Bromine is less active than Chlorine)*

5. $2\text{F}_{2(aq)} + \text{ZrCl}_{4(s)} \rightarrow \text{ZrF}_{4(s)} + 2\text{Cl}_{2(g)}$
*(Fluorine replaces Chlorine. Note: Zirconium typically forms a +4 ion)*

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DOUBLE REPLACEMENT

*Rule: The positive ions switch partners. Check solubility rules to see if a solid precipitate forms.*

Example IV: $\text{AlBr}_{3(aq)} + 3\text{NaOH}_{(aq)} \rightarrow \text{Al(OH)}_{3(s)} + 3\text{NaBr}_{(aq)}$

Example V: $\text{BaCl}_{2(g)} + \text{K}_2\text{SO}_{4(aq)} \rightarrow \text{BaSO}_{4(s)} + 2\text{KCl}_{(aq)}$
*(Note: BaCl₂ is usually aqueous, but balanced as written)*

Example VI: $(\text{NH}_4)_2\text{S}_{(s)} + \text{LiC}_2\text{H}_3\text{O}_{2(aq)} \rightarrow \text{NR}$
*(Both possible products, Lithium Sulfide and Ammonium Acetate, are soluble in water, so no precipitate forms)*

6. $\text{FeCl}_{2(aq)} + \text{K}_2\text{S}_{(aq)} \rightarrow \text{FeS}_{(s)} + 2\text{KCl}_{(aq)}$
*(Iron(II) Sulfide is insoluble)*

7. $\text{CuSO}_{4(aq)} + 2\text{AgNO}_{3(aq)} \rightarrow \text{Ag}_2\text{SO}_{4(s)} + \text{Cu(NO}_3)_{2(aq)}$
*(Silver Sulfate is slightly soluble/insoluble)*

8. $2\text{AlCl}_{3(aq)} + 3\text{Na}_2\text{CO}_{3(aq)} \rightarrow \text{Al}_2(\text{CO}_3)_{3(s)} + 6\text{NaCl}_{(aq)}$
*(Aluminum Carbonate is insoluble)*

9. $(\text{NH}_4)_2\text{SO}_{4(aq)} + \text{BaCl}_{2(aq)} \rightarrow \text{BaSO}_{4(s)} + 2\text{NH}_4\text{Cl}_{(aq)}$
*(Barium Sulfate is insoluble)*

10. $2\text{K}_3\text{PO}_{4(aq)} + 3\text{Fe}_2\text{O}_{3(s)} \rightarrow \text{NR}$
*(Double replacement reactions generally require both reactants to be dissolved in water. Since Iron(III) Oxide is a solid rust that does not dissolve, the reaction does not proceed)*

Final Answer:
SINGLE REPLACEMENT:
Ex I: $2\text{Al} + 3\text{Pb(NO}_3)_2 \rightarrow 3\text{Pb} + 2\text{Al(NO}_3)_3$
Ex II: $\text{Cl}_2 + \text{CuI}_2 \rightarrow \text{CuCl}_2 + \text{I}_2$
Ex III: $2\text{Ag} + \text{Ca(IO}_3)_2 \rightarrow \text{NR}$
1. $\text{Zn} + \text{CuSO}_4 \rightarrow \text{ZnSO}_4 + \text{Cu}$
2. $\text{Cl}_2 + 2\text{KI} \rightarrow 2\text{KCl} + \text{I}_2$
3. $\text{Ni} + \text{MgSO}_4 \rightarrow \text{NR}$
4. $\text{Br}_2 + \text{CaCl}_2 \rightarrow \text{NR}$
5. $2\text{F}_2 + \text{ZrCl}_4 \rightarrow \text{ZrF}_4 + 2\text{Cl}_2$

DOUBLE REPLACEMENT:
Ex IV: $\text{AlBr}_3 + 3\text{NaOH} \rightarrow \text{Al(OH)}_3 + 3\text{NaBr}$
Ex V: $\text{BaCl}_2 + \text{K}_2\text{SO}_4 \rightarrow \text{BaSO}_4 + 2\text{KCl}$
Ex VI: $(\text{NH}_4)_2\text{S} + \text{LiC}_2\text{H}_3\text{O}_2 \rightarrow \text{NR}$
6. $\text{FeCl}_2 + \text{K}_2\text{S} \rightarrow \text{FeS} + 2\text{KCl}$
7. $\text{CuSO}_4 + 2\text{AgNO}_3 \rightarrow \text{Ag}_2\text{SO}_4 + \text{Cu(NO}_3)_2$
8. $2\text{AlCl}_3 + 3\text{Na}_2\text{CO}_3 \rightarrow \text{Al}_2(\text{CO}_3)_3 + 6\text{NaCl}$
9. $(\text{NH}_4)_2\text{SO}_4 + \text{BaCl}_2 \rightarrow \text{BaSO}_4 + 2\text{NH}_4\text{Cl}$
10. $2\text{K}_3\text{PO}_4 + 3\text{Fe}_2\text{O}_3 \rightarrow \text{NR}$