Question

question 1 (4 points)
(03.06 lc)
an induced dipole occurs when one molecule with a permanent dipole repels another molecules electrons, causing the electrons to be more concentrated on one end of the molecule than another.
o a true
o b false
question 2 (4 points)
(03.06 mc)
when comparing h2, nh3, o2, and ch4, which of the following statements is correct?
o a ch4 has the highest boiling point because it experiences dipole-dipole forces.
o b h2 has the strongest intermolecular forces because it has the lowest mass.
o c nh3 has the highest boiling point because it experiences hydrogen bonding
o d o2 has the strongest intermolecular force because it experiences london dispersion forces.
question 3 (4 points)
(03.06 lc)
which statement is true for dipole-dipole forces?
o a they are stronger than hydrogen bonding forces
o b they are weaker than london dispersion forces
o c they occur between ions and polar molecules
o d they occur between polar molecules

Explanation:

Question 1

An induced dipole is formed when a polar molecule (with a permanent dipole) interacts with another molecule. The electron - cloud of the non - polar molecule is distorted. The permanent dipole of the first molecule repels the electrons of the second molecule, causing the electrons to be more concentrated on one end.

• Option a: \(CH_4\) is non - polar (symmetrical tetrahedral structure) and has only London dispersion forces, not dipole - dipole forces.
• Option b: \(H_2\) has very weak London dispersion forces (it is a small non - polar molecule). A lower mass does not mean stronger intermolecular forces. In fact, for non - polar molecules, stronger London dispersion forces are related to larger electron clouds (usually larger molar masses).
• Option c: \(NH_3\) has \(N - H\) bonds. Nitrogen is highly electronegative, and hydrogen bonding (a special type of strong dipole - dipole force) occurs between \(NH_3\) molecules. Hydrogen bonding leads to higher boiling points compared to substances with only London dispersion or regular dipole - dipole forces (when molar masses are comparable).
• Option d: \(O_2\) is non - polar (\(O = O\) double bond, symmetrical) and has only London dispersion forces. London dispersion forces are generally weaker than hydrogen bonding.

• Option a: Hydrogen bonding is a stronger intermolecular force than dipole - dipole forces (for example, \(H_2O\) has hydrogen bonding and higher boiling points compared to many substances with dipole - dipole forces).
• Option b: Dipole - dipole forces are stronger than London dispersion forces for polar molecules of comparable molar mass. For example, \(HCl\) (dipole - dipole) has a higher boiling point than \(F_2\) (London dispersion).
• Option c: Ion - dipole forces occur between ions and polar molecules, not dipole - dipole forces.
• Option d: Dipole - dipole forces occur between polar molecules. The positive end of one polar molecule is attracted to the negative end of another polar molecule.

Answer:

A. True

Question 2