Skip to main content
Pearson+ LogoPearson+ Logo
Ch.13 - Properties of Solutions
All textbooksBrown 15th EditionCh.13 - Properties of SolutionsProblem 14
Chapter 13, Problem 14

Indicate whether each statement is true or false: (a) NaCl dissolves in water but not in benzene (C6H6) because benzene is denser than water. (b) NaCl dissolves in water but not in benzene because water has a large dipole moment and benzene has zero dipole moment. (c) NaCl dissolves in water but not in benzene because the water–ion interactions are stronger than benzene–ion interactions.

Verified step by step guidance
1
Step 1: Understand the solubility principle 'like dissolves like', which means polar substances tend to dissolve in polar solvents, and nonpolar substances dissolve in nonpolar solvents.
Step 2: Analyze statement (a): Consider the density of a solvent and its relevance to solubility. Density is not a determining factor for solubility; instead, the polarity of the solvent is more significant.
Step 3: Analyze statement (b): Recognize that water is a polar solvent with a significant dipole moment, while benzene is nonpolar with a zero dipole moment. NaCl, being ionic, is more likely to dissolve in a polar solvent like water.
Step 4: Analyze statement (c): Consider the interactions between solute and solvent. Water-ion interactions (ion-dipole forces) are generally stronger than benzene-ion interactions, which are weak or nonexistent due to benzene's nonpolarity.
Step 5: Conclude the analysis by determining the truth of each statement based on the principles of solubility and intermolecular forces discussed in the previous steps.

Key Concepts

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

Polarity and Solubility

The principle of 'like dissolves like' explains that polar substances tend to dissolve in polar solvents, while nonpolar substances dissolve in nonpolar solvents. Water is a polar solvent due to its significant dipole moment, allowing it to effectively interact with and dissolve ionic compounds like NaCl. In contrast, benzene is a nonpolar solvent, which does not interact favorably with ionic compounds.
Recommended video:
Guided course
02:38
Molecular Polarity

Ionic Compounds and Solvation

Ionic compounds, such as NaCl, consist of positively and negatively charged ions. When dissolved in water, these ions are surrounded by water molecules, a process known as solvation, which stabilizes the ions in solution. The strong interactions between water molecules and the ions overcome the ionic bonds in NaCl, facilitating its dissolution.
Recommended video:
Guided course
02:11
Ionic Compounds Naming

Dipole Moment

The dipole moment is a measure of the separation of positive and negative charges in a molecule, indicating its polarity. Water has a high dipole moment due to its bent shape and electronegative oxygen atom, making it an effective solvent for ionic compounds. In contrast, benzene has a zero dipole moment, rendering it ineffective for dissolving ionic substances like NaCl.
Recommended video:
Guided course
01:25
Dipole Moment
Related Practice
Textbook Question

Suppose you had a balloon made of some highly flexible semipermeable membrane. The balloon is filled completely with a 0.2 M solution of some solute and is submerged in a 0.1 M solution of the same solute:

Initially, the volume of solution in the balloon is 0.25 L. Assuming the volume outside the semipermeable membrane is large, as the illustration shows, what would you expect for the solution volume inside the balloon once the system has come to equilibrium through osmosis? [Section 13.5]

Textbook Question

The diagrams shown represent an emulsion, a true solution, and a liquid crystal. The colored balls represent different liquid molecules. Which diagram corresponds to which type of mixture? [Section 13.6]

Textbook Question

Indicate the type of solute–solvent interaction that should be most important in each of the following solutions: a. CCl4 in benzene (C6H6),

Textbook Question

Indicate the type of solute–solvent interaction that should be most important in each of the following solutions: b. methanol (CH3OH) in water,

Textbook Question

 Indicate the type of solute–solvent interaction that should be most important in each of the following solutions: c. KBr in water,