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title: "A student mixes \\(100.0\\text{ mL}\\) of \\(2.0 \\times 10^{-3}\\text{ M }\\text{Pb(NO}_3)_2\\text{(aq)}\\) with \\(100.0\\text{ mL}\\) of \\(4.0 \\times 10^{-3}\\text{ M }\\text{NaI(aq)}\\) at \\(25^\\circ\\text{C}\\). The value of \\(K_{sp}\\) for \\(\\text{PbI}_2\\) at this temperature is \\(1.0 \\times 10^{-8}\\). Which of the following correctly predicts whether a precipitate of \\(\\text{PbI}_2\\text{(s)}\\) will form and provides the valid justification?"
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url: "https://nerd-notes.com/ubq/123829/"
date_modified: "2026-09-28T12:30:28+00:00"
---

# A student mixes \(100.0\text{ mL}\) of \(2.0 \times 10^{-3}\text{ M }\text{Pb(NO}_3)_2\text{(aq)}\) with \(100.0\text{ mL}\) of \(4.0 \times 10^{-3}\text{ M }\text{NaI(aq)}\) at \(25^\circ\text{C}\). The value of \(K_{sp}\) for \(\text{PbI}_2\) at this temperature is \(1.0 \times 10^{-8}\). Which of the following correctly predicts whether a precipitate of \(\text{PbI}_2\text{(s)}\) will form and provides the valid justification?

A student mixes \(100.0\text{ mL}\) of \(2.0 \times 10^{-3}\text{ M }\text{Pb(NO}_3)_2\text{(aq)}\) with \(100.0\text{ mL}\) of \(4.0 \times 10^{-3}\text{ M }\text{NaI(aq)}\) at \(25^\circ\text{C}\). The value of \(K_{sp}\) for \(\text{PbI}_2\) at this temperature is \(1.0 \times 10^{-8}\). Which of the following correctly predicts whether a precipitate of \(\text{PbI}_2\text{(s)}\) will form and provides the valid justification?

- **A.** A precipitate will form because \(Q = 3.2 \times 10^{-8}\), which is greater than \(K_{sp}\).
- **B.** A precipitate will not form because \(Q = 4.0 \times 10^{-9}\), which is less than \(K_{sp}\).
- **C.** A precipitate will form because \(Q = 2.0 \times 10^{-6}\), which is greater than \(K_{sp}\).
- **D.** A precipitate will not form because \(Q = 1.0 \times 10^{-9}\), which is less than \(K_{sp}\).

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123829/*