Chapter 12, Problem 12.49P

(a)

Interpretation Introduction

Interpretation:

The liquid among the following pair that has a higher vapor pressure at a given temperature is to be determined.

${\text{C}}_{\text{2}}{\text{H}}_6$ or ${\text{C}}_4{\text{H}}_{10}$

Concept introduction:

Intermolecular forces operate between the molecules so changes with change in the phase and effects with physical properties of the substance. In intermolecular forces, the bond is formed between two molecules with partial charges that are present relatively far away from each other. The types of intermolecular forces are as follows:

1. Ion-dipole: Ion-dipole forces are the attractive forces that exist between an ion and a polar molecule.

2. Hydrogen bond: Hydrogen bonding is the attractive forces that exist between the molecule with a hydrogen atom bonded to an electronegative atom like fluorine, nitrogen, and oxygen of one molecule and an electronegative atom of another molecule.

3. Dipole-dipole: Dipole-dipole is the attractive forces that exist between two polar molecules that have a permanent dipole.

4. Ion-induced dipole: Ion-induced dipole is the attractive forces that exist between the ion and a nonpolar molecule.

5. Dipole-induced dipole: Dipole-induced dipole is the attractive forces that exist between a polar and a nonpolar molecule.

6. Dispersion forces: In dispersion forces, a temporary dipole is generated on one molecule that further induces a temporary dipole on the molecule adjacent to it. The temporary dipole results in the attraction between opposite charges and dispersion forces exist in the molecule. All the atoms and molecules exhibit dispersion forces.

The vapor pressure of a compound decreases when the strength of intermolecular forces present between the molecules. The vaporization of a liquid occurs when the intermolecular forces between the molecules break and the molecules are free to vaporize. The increasing order of strength is as follows:

$\text{dispersion forces}<\text{dipole}-\text{dipole forces}<\text{hydrogen bonds}<\text{ion}-\text{dipole forces}$

(b)

Interpretation Introduction

Interpretation:

The liquid among the following pair that has a higher vapor pressure at a given temperature is to be determined.

${\text{CH}}_3{\text{CH}}_2\text{OH}$ or ${\text{CH}}_3{\text{CH}}_2\text{F}$

Concept introduction:

Intermolecular forces operate between the molecules so changes with change in the phase and effects with physical properties of the substance. In intermolecular forces, the bond is formed between two molecules with partial charges that are present relatively far away from each other. The types of intermolecular forces are as follows:

1. Ion-dipole: Ion-dipole forces are the attractive forces that exist between an ion and a polar molecule.

2. Hydrogen bond: Hydrogen bonding is the attractive forces that exist between the molecule with a hydrogen atom bonded to an electronegative atom like fluorine, nitrogen, and oxygen of one molecule and an electronegative atom of another molecule.

3. Dipole-dipole: Dipole-dipole is the attractive forces that exist between two polar molecules that have a permanent dipole.

4. Ion-induced dipole: Ion-induced dipole is the attractive forces that exist between the ion and a nonpolar molecule.

5. Dipole-induced dipole: Dipole-induced dipole is the attractive forces that exist between a polar and a nonpolar molecule.

6. Dispersion forces: In dispersion forces, a temporary dipole is generated on one molecule that further induces a temporary dipole on the molecule adjacent to it. The temporary dipole results in the attraction between opposite charges and dispersion forces exist in the molecule. All the atoms and molecules exhibit dispersion forces.

The vapor pressure of a compound decreases when the strength of intermolecular forces present between the molecules. The vaporization of a liquid occurs when the intermolecular forces between the molecules break and the molecules are free to vaporize. The increasing order of strength is as follows:

$\text{dispersion forces}<\text{dipole}-\text{dipole forces}<\text{hydrogen bonds}<\text{ion}-\text{dipole forces}$

(c)

Interpretation Introduction

Interpretation:

The liquid among the following pair that has the higher vapor pressure at a given temperature is to be determined.

${\text{NH}}_3$ or ${\text{PH}}_3$

Concept introduction:

Intermolecular forces operate between the molecules so changes with change in the phase and effects with physical properties of the substance. In intermolecular forces, the bond is formed between two molecules with partial charges that are present relatively far away from each other. The types of intermolecular forces are as follows:

1. Ion-dipole: Ion-dipole forces are the attractive forces that exist between an ion and a polar molecule.

2. Hydrogen bond: Hydrogen bonding is the attractive forces that exist between the molecule with a hydrogen atom bonded to an electronegative atom like fluorine, nitrogen, and oxygen of one molecule and an electronegative atom of another molecule.

3. Dipole-dipole: Dipole-dipole is the attractive forces that exist between two polar molecules that have a permanent dipole.

4. Ion-induced dipole: Ion-induced dipole is the attractive forces that exist between the ion and a nonpolar molecule.

5. Dipole-induced dipole: Dipole-induced dipole is the attractive forces that exist between a polar and a nonpolar molecule.

6. Dispersion forces: In dispersion forces, a temporary dipole is generated on one molecule that further induces a temporary dipole on the molecule adjacent to it. The temporary dipole results in the attraction between opposite charges and dispersion forces exist in the molecule. All the atoms and molecules exhibit dispersion forces.

The vapor pressure of a compound decreases when the strength of intermolecular forces present between the molecules. The vaporization of a liquid occurs when the intermolecular forces between the molecules break and the molecules are free to vaporize. The increasing order of strength is as follows:

$\text{dispersion forces}<\text{dipole}-\text{dipole forces}<\text{hydrogen bonds}<\text{ion}-\text{dipole forces}$