Solved Worksheet 4 (continued) Equation Writing and | Chegg.com - Free Printable

To solve and balance the given double displacement reaction equations, we need to follow these steps:

1. Identify the reactants and predict the products:
- In a double displacement reaction, the cations and anions of the two reactants switch places to form two new compounds.
- Check if any of the products are insoluble (precipitates), gases, or water, as these will drive the reaction.

2. Write the unbalanced equation:
- Write the formulas of the predicted products based on the switching of ions.

3. Balance the equation:
- Ensure that the number of atoms of each element is the same on both sides of the equation.

Let's solve each problem step by step:

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1. KCl + AgNO₃

- Reactants: KCl (potassium chloride) and AgNO₃ (silver nitrate)
- Products: AgCl (silver chloride, which is insoluble) and KNO₃ (potassium nitrate)
- Unbalanced Equation: KCl + AgNO₃ → AgCl + KNO₃
- Balanced Equation: The equation is already balanced.

Final Answer:
\[
\boxed{\text{KCl + AgNO}_3 \rightarrow \text{AgCl} + \text{KNO}_3}
\]

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2. SrCl₂ + H₂SO₄

- Reactants: SrCl₂ (strontium chloride) and H₂SO₄ (sulfuric acid)
- Products: SrSO₄ (strontium sulfate, which is insoluble) and 2HCl (hydrochloric acid)
- Unbalanced Equation: SrCl₂ + H₂SO₄ → SrSO₄ + 2HCl
- Balanced Equation: The equation is already balanced.

Final Answer:
\[
\boxed{\text{SrCl}_2 + \text{H}_2\text{SO}_4 \rightarrow \text{SrSO}_4 + 2\text{HCl}}
\]

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3. Na₂CO₃ + HCl

- Reactants: Na₂CO₃ (sodium carbonate) and HCl (hydrochloric acid)
- Products: NaCl (sodium chloride), CO₂ (carbon dioxide, gas), and H₂O (water)
- Unbalanced Equation: Na₂CO₃ + HCl → 2NaCl + CO₂ + H₂O
- Balanced Equation: To balance, we need 2 moles of HCl.
\[
\text{Na}_2\text{CO}_3 + 2\text{HCl} \rightarrow 2\text{NaCl} + \text{CO}_2 + \text{H}_2\text{O}
\]

Final Answer:
\[
\boxed{\text{Na}_2\text{CO}_3 + 2\text{HCl} \rightarrow 2\text{NaCl} + \text{CO}_2 + \text{H}_2\text{O}}
\]

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4. Na₂SO₃ + HCl

- Reactants: Na₂SO₃ (sodium sulfite) and HCl (hydrochloric acid)
- Products: NaCl (sodium chloride), SO₂ (sulfur dioxide, gas), and H₂O (water)
- Unbalanced Equation: Na₂SO₃ + HCl → 2NaCl + SO₂ + H₂O
- Balanced Equation: To balance, we need 2 moles of HCl.
\[
\text{Na}_2\text{SO}_3 + 2\text{HCl} \rightarrow 2\text{NaCl} + \text{SO}_2 + \text{H}_2\text{O}
\]

Final Answer:
\[
\boxed{\text{Na}_2\text{SO}_3 + 2\text{HCl} \rightarrow 2\text{NaCl} + \text{SO}_2 + \text{H}_2\text{O}}
\]

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5. NaOH + NH₄NO₃

- Reactants: NaOH (sodium hydroxide) and NH₄NO₃ (ammonium nitrate)
- Products: NaNO₃ (sodium nitrate) and NH₃ (ammonia, gas) + H₂O (water)
- Unbalanced Equation: NaOH + NH₄NO₃ → NaNO₃ + NH₃ + H₂O
- Balanced Equation: The equation is already balanced.

Final Answer:
\[
\boxed{\text{NaOH} + \text{NH}_4\text{NO}_3 \rightarrow \text{NaNO}_3 + \text{NH}_3 + \text{H}_2\text{O}}
\]

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6. AlCl₃ + NaOH

- Reactants: AlCl₃ (aluminum chloride) and NaOH (sodium hydroxide)
- Products: Al(OH)₃ (aluminum hydroxide, which is insoluble) and 3NaCl (sodium chloride)
- Unbalanced Equation: AlCl₃ + NaOH → Al(OH)₃ + 3NaCl
- Balanced Equation: To balance, we need 3 moles of NaOH.
\[
\text{AlCl}_3 + 3\text{NaOH} \rightarrow \text{Al(OH)}_3 + 3\text{NaCl}
\]

Final Answer:
\[
\boxed{\text{AlCl}_3 + 3\text{NaOH} \rightarrow \text{Al(OH)}_3 + 3\text{NaCl}}
\]

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7. K₂Cr₂O₇ + Pb(NO₃)₂

- Reactants: K₂Cr₂O₇ (potassium dichromate) and Pb(NO₃)₂ (lead(II) nitrate)
- Products: PbCr₂O₇ (lead(II) dichromate, which is insoluble) and 2KNO₃ (potassium nitrate)
- Unbalanced Equation: K₂Cr₂O₇ + Pb(NO₃)₂ → PbCr₂O₇ + 2KNO₃
- Balanced Equation: The equation is already balanced.

Final Answer:
\[
\boxed{\text{K}_2\text{Cr}_2\text{O}_7 + \text{Pb(NO}_3)_2 \rightarrow \text{PbCr}_2\text{O}_7 + 2\text{KNO}_3}
\]

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8. K₃PO₄ + Ca(OH)₂

- Reactants: K₃PO₄ (potassium phosphate) and Ca(OH)₂ (calcium hydroxide)
- Products: Ca₃(PO₄)₂ (calcium phosphate, which is insoluble) and 3KOH (potassium hydroxide)
- Unbalanced Equation: K₃PO₄ + Ca(OH)₂ → Ca₃(PO₄)₂ + 3KOH
- Balanced Equation: To balance, we need 3 moles of Ca(OH)₂ and 2 moles of K₃PO₄.
\[
2\text{K}_3\text{PO}_4 + 3\text{Ca(OH)}_2 \rightarrow \text{Ca}_3(\text{PO}_4)_2 + 6\text{KOH}
\]

Final Answer:
\[
\boxed{2\text{K}_3\text{PO}_4 + 3\text{Ca(OH)}_2 \rightarrow \text{Ca}_3(\text{PO}_4)_2 + 6\text{KOH}}
\]

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9. (NH₄)₂CO₃ + AgNO₃

- Reactants: (NH₄)₂CO₃ (ammonium carbonate) and AgNO₃ (silver nitrate)
- Products: Ag₂CO₃ (silver carbonate, which is insoluble) and 2NH₄NO₃ (ammonium nitrate)
- Unbalanced Equation: (NH₄)₂CO₃ + AgNO₃ → Ag₂CO₃ + 2NH₄NO₃
- Balanced Equation: To balance, we need 2 moles of AgNO₃.
\[
(\text{NH}_4)_2\text{CO}_3 + 2\text{AgNO}_3 \rightarrow \text{Ag}_2\text{CO}_3 + 2\text{NH}_4\text{NO}_3
\]

Final Answer:
\[
\boxed{(\text{NH}_4)_2\text{CO}_3 + 2\text{AgNO}_3 \rightarrow \text{Ag}_2\text{CO}_3 + 2\text{NH}_4\text{NO}_3}
\]

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10. K₂CO₃ + NiBr₂

- Reactants: K₂CO₃ (potassium carbonate) and NiBr₂ (nickel(II) bromide)
- Products: NiCO₃ (nickel(II) carbonate, which is insoluble) and 2KBr (potassium bromide)
- Unbalanced Equation: K₂CO₃ + NiBr₂ → NiCO₃ + 2KBr
- Balanced Equation: The equation is already balanced.

Final Answer:
\[
\boxed{\text{K}_2\text{CO}_3 + \text{NiBr}_2 \rightarrow \text{NiCO}_3 + 2\text{KBr}}
\]

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Summary of Final Answers:

1. \(\boxed{\text{KCl + AgNO}_3 \rightarrow \text{AgCl} + \text{KNO}_3}\)
2. \(\boxed{\text{SrCl}_2 + \text{H}_2\text{SO}_4 \rightarrow \text{SrSO}_4 + 2\text{HCl}}\)
3. \(\boxed{\text{Na}_2\text{CO}_3 + 2\text{HCl} \rightarrow 2\text{NaCl} + \text{CO}_2 + \text{H}_2\text{O}}\)
4. \(\boxed{\text{Na}_2\text{SO}_3 + 2\text{HCl} \rightarrow 2\text{NaCl} + \text{SO}_2 + \text{H}_2\text{O}}\)
5. \(\boxed{\text{NaOH} + \text{NH}_4\text{NO}_3 \rightarrow \text{NaNO}_3 + \text{NH}_3 + \text{H}_2\text{O}}\)
6. \(\boxed{\text{AlCl}_3 + 3\text{NaOH} \rightarrow \text{Al(OH)}_3 + 3\text{NaCl}}\)
7. \(\boxed{\text{K}_2\text{Cr}_2\text{O}_7 + \text{Pb(NO}_3)_2 \rightarrow \text{PbCr}_2\text{O}_7 + 2\text{KNO}_3}\)
8. \(\boxed{2\text{K}_3\text{PO}_4 + 3\text{Ca(OH)}_2 \rightarrow \text{Ca}_3(\text{PO}_4)_2 + 6\text{KOH}}\)
9. \(\boxed{(\text{NH}_4)_2\text{CO}_3 + 2\text{AgNO}_3 \rightarrow \text{Ag}_2\text{CO}_3 + 2\text{NH}_4\text{NO}_3}\)
10. \(\boxed{\text{K}_2\text{CO}_3 + \text{NiBr}_2 \rightarrow \text{NiCO}_3 + 2\text{KBr}}\)