Skip to main content
Ch.18 - Aqueous Ionic Equilibrium
Tro - Chemistry: A Molecular Approach 6th Edition
Tro6th EditionChemistry: A Molecular ApproachISBN: 9780137832217Not the one you use?Change textbook
All textbooksTro 6th EditionCh.18 - Aqueous Ionic EquilibriumProblem 107
Chapter 18, Problem 107

A solution containing sodium fluoride is mixed with one containing calcium nitrate to form a solution that is 0.015 M in NaF and 0.010 M in Ca(NO3)2. Does a precipitate form in the mixed solution? If so, identify the precipitate.

Verified step by step guidance
1
Identify the possible precipitate by considering the ions present: Na^+, F^-, Ca^{2+}, and NO_3^-. The potential precipitate is CaF_2, as it is insoluble in water.
Write the balanced chemical equation for the formation of the precipitate: Ca^{2+} (aq) + 2F^- (aq) \(\rightarrow\) CaF_2 (s).
Determine the solubility product constant (K_{sp}) for CaF_2 from a reliable source.
Calculate the ion product (Q) for CaF_2 using the concentrations of Ca^{2+} and F^- in the mixed solution: Q = [Ca^{2+}][F^-]^2.
Compare the ion product (Q) to the solubility product constant (K_{sp}): If Q > K_{sp}, a precipitate will form; if Q < K_{sp}, no precipitate will form.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Solubility Product Constant (Ksp)

The solubility product constant (Ksp) is a numerical value that represents the extent to which a compound can dissolve in water. It is specific to each ionic compound and is determined at a given temperature. When the product of the concentrations of the ions in a solution exceeds the Ksp, a precipitate will form, indicating that the solution is supersaturated.
Recommended video:
Guided course
01:47
Solubility Product Constant

Ionic Equilibrium

Ionic equilibrium refers to the balance between the dissolved ions in a solution and the solid phase of a compound. In the context of precipitation reactions, it is essential to understand how the concentrations of ions change when two solutions are mixed, and how these changes can lead to the formation of a solid precipitate if the ionic product exceeds the Ksp.

Common Ion Effect

The common ion effect describes the decrease in solubility of an ionic compound when a common ion is added to the solution. In this scenario, the presence of fluoride ions from sodium fluoride can affect the solubility of calcium fluoride (CaF2) if it forms, leading to a potential precipitate. Understanding this effect is crucial for predicting whether a precipitate will form when mixing solutions.
Recommended video:
Guided course
02:53
Common Ion Effect
Related Practice
Textbook Question

Calculate the molar solubility of MX (Ksp = 1.27⨉10-36) in each liquid or solution. b. 0.25 M MCl2

738
views
Textbook Question

Determine if each compound is more soluble in acidic solution than it is in pure water. Explain. a. BaCO3 b. CuS c. AgCl d. PbI2

3384
views
Textbook Question

Predict whether a precipitate will form if you mix 75.0 mL of a NaOH solution with pOH = 2.58 with 125.0 mL of a 0.018 M MgCl2 solution. Identify the precipitate, if any.

1277
views
Textbook Question

Calculate the molar solubility of calcium hydroxide in a solution buffered at each pH. a. pH = 4

2628
views