Precipitation reactions and solubility rules Knowledge-Based Practice

Questions

1. 1.

   An aqueous solution contains both $\text{Ag}^+$ and $\text{Cu}^{2+}$ cations. Which of the following reagents can be added in aqueous form to selectively precipitate $\text{Ag}^+$ while leaving $\text{Cu}^{2+}$ dissolved in solution?

   • A) Sodium chloride, $\text{NaCl}$
   • B) Sodium hydroxide, $\text{NaOH}$
   • C) Sodium sulfide, $\text{Na}_2\text{S}$
   • D) Sodium carbonate, $\text{Na}_2\text{CO}_3$
2. 2.

   Which of the following represents the balanced net ionic equation for the precipitation reaction between aqueous iron(III) nitrate and aqueous sodium hydroxide?

   • A) $\text{Na}^+\text{(aq)} + \text{NO}_3^-\text{(aq)} \rightarrow \text{NaNO}_3\text{(s)}$
   • B) $\text{Fe}^{3+}\text{(aq)} + 3\text{OH}^-\text{(aq)} \rightarrow \text{Fe(OH)}_3\text{(s)}$
   • C) $\text{Fe(NO}_3)_3\text{(aq)} + 3\text{NaOH(aq)} \rightarrow \text{Fe(OH)}_3\text{(s)} + 3\text{NaNO}_3\text{(aq)}$
   • D) $\text{Fe}^{3+}\text{(aq)} + 3\text{NO}_3^-\text{(aq)} + 3\text{Na}^+\text{(aq)} + 3\text{OH}^-\text{(aq)} \rightarrow \text{Fe(OH)}_3\text{(s)} + 3\text{Na}^+\text{(aq)} + 3\text{NO}_3^-\text{(aq)}$
3. 3.

   When aqueous solutions of barium chloride, $\text{BaCl}_2$, and sodium sulfate, $\text{Na}_2\text{SO}_4$, are mixed, a precipitate forms. Which of the following pairs of ions represents the spectator ions in this reaction?

   • A) $\text{Na}^+$ and $\text{Cl}^-$
   • B) $\text{Ba}^{2+}$ and $\text{SO}_4^{2-}$
   • C) $\text{Ba}^{2+}$ and $\text{Cl}^-$
   • D) $\text{Na}^+$ and $\text{SO}_4^{2-}$
4. 4.

   According to general solubility rules, which of the following pairs of aqueous solutions produces an insoluble precipitate when mixed?

   • A) $\text{NaCl(aq)}$ and $\text{KNO}_3\text{(aq)}$
   • B) $\text{NH}_4\text{Cl(aq)}$ and $\text{CuSO}_4\text{(aq)}$
   • C) $\text{LiBr(aq)}$ and $\text{Mg(NO}_3)_2\text{(aq)}$
   • D) $\text{BaCl}_2\text{(aq)}$ and $\text{Na}_2\text{SO}_4\text{(aq)}$
5. 5.

   When aqueous solutions of lead(II) nitrate, $\text{Pb(NO}_3)_2$, and potassium iodide, $\text{KI}$, are mixed, a double displacement precipitation reaction occurs. Which of the following is the chemical formula of the insoluble precipitate that forms?

   • A) $\text{KNO}_3$
   • B) $\text{PbI}$
   • C) $\text{PbI}_2$
   • D) $\text{K}_2\text{NO}_3$

Answers and step-by-step solutions appear after you finish the test.