Chapter 15, Problem 68A

(a)

Interpretation Introduction

Interpretation: Whether ${\text{CCl}}_{\text{4}}$ dissolves in water or gasoline needs to be determined.

Concept Introduction: The dissolution of a solute in a solvent is based on the principle of “like dissolve like”. Thus, polar solutes dissolve in polar solvents and non-polar solutes dissolve in a non-polar solvents.

Water is a well-known polar solvent and gasoline is a non-polar solvent. To identify the compounds dissolved in water and gasoline, whether the compound is polar or non-polar needs to be determined first.

Explanation of Solution

The given compound is ${\text{CCl}}_{\text{4}}$ , here, chlorine is more electronegative than carbon. Thus, it has a partial negative charge and carbon has a partial positive charge. Therefore, the C-Cl bond is polar. There are 4 C-Cl bonds in ${\text{CCl}}_{\text{4}}$ . Since there is no lone pair of electrons in the central carbon atom, the geometry of the molecule is tetrahedral. Here, the dipole moments of two C-Cl bonds get canceled by the dipole moments of the other two C-Cl bonds. The dipole moment of the compound is zero, thus, it is non-polar.

According to the principle of “like dissolve like”, ${\text{CCl}}_{\text{4}}$ will be soluble in a non-polar solvent which is gasoline.

(b)

Interpretation Introduction

Interpretation: Whether ${\text{CH}}_{\text{4}}$ dissolves in water or gasoline needs to be determined.

Concept Introduction: The dissolution of a solute in a solvent is based on the principle of “like dissolve like”. Thus, polar solutes dissolve in polar solvents and non-polar solutes dissolve in a non-polar solvents.

Water is a well-known polar solvent and gasoline is a non-polar solvent. To identify the compounds dissolved in water and gasoline, whether the compound is polar or non-polar needs to be determined first.

Explanation of Solution

The given compound is methane or ${\text{CH}}_{\text{4}}$ . The electronegativity difference between C and H is very small thus, C-H bonds are not considered polar bonds. Since there is no polar bond in ${\text{CH}}_{\text{4}}$ , it is non-polar in nature.

According to the principle of “like dissolve like”, ${\text{CH}}_{\text{4}}$ will be soluble in a non-polar solvent which is gasoline.

(c)

Interpretation Introduction

Interpretation: Whether ${\text{Na}}_{\text{2}}{\text{SO}}_{\text{4}}$ dissolves in water or gasoline needs to be determined.

Concept Introduction: The dissolution of a solute in a solvent is based on the principle of “like dissolve like”. Thus, polar solutes dissolve in polar solvents and non-polar solutes dissolve in a non-polar solvents.

Water is a well-known polar solvent and gasoline is a non-polar solvent. To identify the compounds dissolved in water and gasoline, whether the compound is polar or non-polar needs to be determined first.

Explanation of Solution

The given compound is ${\text{Na}}_{\text{2}}{\text{SO}}_{\text{4}}$ . It is an ionic compound; thus, it is polar. It gets dissociates into sodium and sulfate ions. Now, according to the principle of “like dissolve like” being polar, ${\text{Na}}_{\text{2}}{\text{SO}}_{\text{4}}$ is soluble in water, not gasoline.

(d)

Interpretation Introduction

Interpretation: Whether $\text{KCl}$ dissolves in water or gasoline needs to be determined.

Concept Introduction: The dissolution of a solute in a solvent is based on the principle of “like dissolve like”. Thus, polar solutes dissolve in polar solvents and non-polar solutes dissolve in a non-polar solvents.

Water is a well-known polar solvent and gasoline is a non-polar solvent. To identify the compounds dissolved in water and gasoline, whether the compound is polar or non-polar needs to be determined first.

Explanation of Solution

The given compound is $\text{KCl}$ . It is an ionic compound; thus, it is polar. It gets dissociates into potassium and chloride ions. Now, according to the principle of “like dissolve like” being polar, $\text{KCl}$ is soluble in water, not gasoline.