(a)
Interpretation: The given compounds must be arranged in increasing order of strength of their intermolecular forces.
Concept introduction: Intermolecular forces are those interactions among molecules by which the molecules either attract or repel each other. There are mainly four types of intermolecular interactions these are electrostatic, Van der Waals, dipole-dipole and hydrogen bonding. The electrostatic force is strongest and among the three types of intermolecular forces in covalent compounds van der Waals forces are weakest, dipole-dipole is intermediate and hydrogen bonding is the strongest.
Answer to Problem 3.28P
Increasing intermolecular forces
Explanation of Solution
The CH3CH3, ethane consists of only C – H and C – C bonds and these bonds are nonpolar thus the ethane has no permanent dipole moment therefore, ethane molecules are attracted to each other only by van der Waals forces.
The CH3Cl, chloromethane consists of C – H and C – Cl bonds among which C – Cl bond is polar since Cl is highly electronegative atom thus the chloromethane molecule possesses a permanent dipole moment. Therefore, chloromethane molecules are attracted to each other not only by van der Waals forces but also by dipole-dipole interactions.
The CH3NH2, methylamine consists of C – H, N – H and C – Cl bonds among which C – N and N – H bonds are polar since N is an electronegative atom thus the methylamine molecule possesses a permanent dipole moment. Therefore, methylamine molecules are attracted to each other not only by van der Waals forces but also by dipole-dipole interactions and since it contains a H-atom attached to an electronegative N-atom so CH3NH2 molecules will also be linked through Hydrogen bonding.
Increasing intermolecular forces
(b)
Interpretation: The given compounds must be arranged in increasing order of strength of their intermolecular forces.
Concept introduction: Intermolecular forces are those interactions among molecules by which the molecules either attract or repel each other. There are mainly four types of intermolecular interactions these are electrostatic, Van der Waals, dipole-dipole and hydrogen bonding. The electrostatic force is strongest and among the three types of intermolecular forces in covalent compounds van der Waals forces are weakest, dipole-dipole is intermediate and hydrogen bonding is the strongest.
Answer to Problem 3.28P
Increasing intermolecular forces
Explanation of Solution
The CH3Br molecule consists of only C – H and C – Br bonds among which C – Br bond is polar thus this molecule has permanent dipole moment therefore; these molecules are attracted towards each other not only by van der Waals forces but also by dipole-dipole interactions.
The CH3I molecule consists of only C – H and C – I bonds among which C – I bond is polar thus this molecule has permanent dipole moment therefore; these molecules are attracted towards each other not only by van der Waals forces but also by dipole-dipole interactions.
The CH3Cl molecule consists of only C – H and C – Cl bonds among which C – Cl bond is polar thus this molecule has permanent dipole moment therefore; these molecules are attracted towards each other not only by van der Waals forces but also by dipole-dipole interactions.
All these molecules are attracted to each other by van der Waals forces and dipole-dipole interactions. But with increase in size of the atom here halogen atoms the polarizability increases which results in the increase of intermolecular forces. Here, the size of halogen atoms increase with increase in
Increasing intermolecular forces
(c)
Interpretation: The given compounds must be arranged in increasing order of strength of their intermolecular forces.
Concept introduction: Intermolecular forces are those interactions among molecules by which the molecules either attract or repel each other. There are mainly four types of intermolecular interactions these are electrostatic, Van der Waals, dipole-dipole and hydrogen bonding. The electrostatic force is strongest and among the three types of intermolecular forces in covalent compounds van der Waals forces are weakest, dipole-dipole is intermediate and hydrogen bonding is the strongest.
Answer to Problem 3.28P
Increasing intermolecular forces
Explanation of Solution
The
The
The
Increasing intermolecular forces
(d)
Interpretation: The given compounds must be arranged in increasing order of strength of their intermolecular forces.
Concept introduction: Intermolecular forces are those interactions among molecules by which the molecules either attract or repel each other. There are mainly four types of intermolecular interactions these are electrostatic, Van der Waals, dipole-dipole and hydrogen bonding. The electrostatic force is strongest and among the three types of intermolecular forces in covalent compounds van der Waals forces are weakest, dipole-dipole is intermediate and hydrogen bonding is the strongest.
Answer to Problem 3.28P
Increasing intermolecular forces
Explanation of Solution
The CH3Cl molecule consists of only C – H and C – Cl bonds among which C – Cl bond is polar thus this molecule has permanent dipole moment therefore; these molecules are attracted towards each other not only by van der Waals forces but also by dipole-dipole interactions.
The CH3OH, methanol consists of C – H and O – H bonds among which O – H bond are polar since O is an electronegative atom thus the methanol molecule possesses a permanent dipole moment. Therefore, methanol molecules are attracted to each other not only by van der Waals forces but also by dipole-dipole interactions and since it contains a H-atom attached to an electronegative O-atom so CH3OH molecules will also be linked through Hydrogen bonding.
The NaCl molecule consists of only an ionic bond among Na+ and Cl- ions thus, these molecules are attracted towards each other by electrostatic interactions.
Increasing intermolecular forces
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Organic Chemistry (Looseleaf) - With Access
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