Question 1

Which of the following best explains why water has a high surface tension compared to most other liquids?

Accepted Answer

Water molecules form hydrogen bonds, which are strong intermolecular forces that pull molecules at the surface inward.

Question 2

A student places a drop of an unknown liquid on both a glass and a plastic slide. The drop spreads out on the glass but beads up on the plastic. What can be inferred about the polarity of the unknown liquid?

Accepted Answer

The liquid is polar because it interacts more with the polar glass surface.

Question 3

Which of the following correctly lists the four intermolecular forces studied, from strongest to weakest?

Accepted Answer

Ion-dipole \u003e Hydrogen bonding \u003e Dipole-dipole \u003e London dispersion

Question 4

What is a micelle, and why does it form in water when soap is added?

Accepted Answer

A micelle is a spherical structure where the hydrophobic tails of amphipathic molecules are shielded from water, while the hydrophilic heads face outward.

Question 5

Sodium stearate is considered amphipathic. What does this mean, and how does it relate to its cleaning action?

Accepted Answer

It has both polar (hydrophilic) and nonpolar (hydrophobic) regions, allowing it to interact with both water and grease.

Question 6

Which of the following best describes the effect of a surfactant on the surface tension of water?

Accepted Answer

A surfactant decreases surface tension by disrupting hydrogen bonds between water molecules.

Question 7

According to VSEPR Theory, what is the molecular geometry of a molecule with 4 bonding pairs and 0 lone pairs on the central atom?

Accepted Answer

Tetrahedral

Question 8

How does electron group geometry differ from molecular geometry?

Accepted Answer

Electron group geometry considers both atoms and lone pairs, while molecular geometry considers only the positions of atoms.

Question 9

Which of the following molecules would you expect to be soluble in methane ($$CH_4$$)?

Accepted Answer

$$CO_2$$

Question 10

A molecule has the following Lewis structure: $$NH_3. $$What is its molecular geometry and why?

Accepted Answer

Trigonal pyramidal, because it has three bonding pairs and one lone pair.

Question 11

Which intermolecular force is primarily responsible for the interaction between two $$CH_4$$ molecules?

Accepted Answer

London dispersion forces

Question 12

How does increasing the length of a nonpolar molecule affect its intermolecular forces?

Accepted Answer

It increases the strength of London dispersion forces due to more electrons and greater polarizability.

Question 13

Which of the following best describes how to use dipoles to determine the overall polarity of a molecule?

Accepted Answer

Add up all the bond dipoles; if they cancel out, the molecule is nonpolar.

Question 14

Which of the following molecules would have a bent molecular geometry?

Accepted Answer

$$H_2O$$

Question 15

Which scenario best illustrates the concept of 'like dissolves like'?

Accepted Answer

Mixing $$CO_2 ($$nonpolar) with $$CH_4 ($$nonpolar) results in a homogeneous solution.

Question 16

Which of the following is NOT a major molecular geometry according to VSEPR Theory?

Accepted Answer

Octahedral

Question 17

A molecule with 2 bonding pairs and 2 lone pairs on the central atom will have which molecular geometry?

Accepted Answer

Bent

Question 18

Which intermolecular force is most important for the solubility of $$NH_3 in $$water?

Accepted Answer

Hydrogen bonding

Question 19

Which of the following best explains why sodium stearate can remove grease from a surface?

Accepted Answer

Its hydrophobic tail dissolves in grease while its hydrophilic head interacts with water, allowing grease to be emulsified and washed away.

Molecular Geometry & Intermolecular Forces: Study Guide Notes

Guida di studio - Domande di pratica

Study guide - Flashcard