Module 4d Intermolecular Forces

Question 1

What is an intermolecular force?

Answer 1

Force of attraction that occurs between atoms, molecules, and ions due to their proximity in space to each other.

Due to large number of interactions, intermolecular forces appear stronger.

Question 2

What are applications of intermolecular forces?

Answer 2

Surface Tension
Capillary Action
Viscosity
Receptor Binding
Phase Changes
Solubility

Question 3

The stronger the intermolecular forces, the _________ energy required to increase the surface area.

Answer 3

More

Question 4

The intermolecular forces in water is __________. Its surface tension will resist the ability of the water to spread out.

Answer 4

High

Question 5

What is capillary action?

Answer 5

The spontaneous rising of a liquid in a narrow tube or the movement of a liquid up a piece of paper against the pull of gravity.

The result of cohesive and adhesive forces.

Question 6

What is viscosity?

Answer 6

Measure of a liquid’s resistance to flow.

The amount of energy necessary to move an object through a fluid.

Molecule size plays an important role (greater potential for more intermolecular force interactions)

Question 7

The vast majority of drug compounds bind to receptors through __________ rather than through formation of ___________.

Answer 7

Intermolecular Forces

Chemical Bonds

Question 8

A phase change is a representation of the changes in the phase of a substance with respect to _________ and _________.

Answer 8

Temperature

Pressure

Question 9

Changes in _________ do not break chemical bonds.

Answer 9

phase

Question 10

What is solubility?

Answer 10

Ability to dissolve.

Like dissolves like. Polar compounds likes to be soluble in polar solvents.

Depends, in part, on attractive forces of the solute and solvent.

Question 11

Substances with similar ____________ will be soluble (solid in liquid) or miscible (liquid in liquid).

Answer 11

polarity

Question 12

List the intermolecular forces from weakest to strongest.

Answer 12

Van der Waals (London Dispersion Forces)

Dipole-Dipole Interactions

Hydrogen Bonding

Ion-Dipole

Electrostatic Interactions

Covalent

Question 13

What are Van der Waals Interaction?

Answer 13

Weakest of the IMF. Most common interactions.

Interaction arising from the formation of induced dipoles between two non-polar molecules (or portions of molecules)

C-C bonds

Question 14

What are dipole-dipole interactions?

Answer 14

Occurs in all polar molecules.
Relative strong interactions, but depends on the nature of individual dipoles involved.

Oxygen partial negative charge to Carbon partial positive charge

Question 15

What is hydrogen bonding?

What are the two types?

What elements make hydrogen bonding the strongest?

Answer 15

Very strong, specialized dipole-dipole interactions.

H-bond donors- molecule providing the hydrogen. -OH, amines, amides, carboxylic acids.

H-bond acceptors- molecule that attracts the hydrogen. Any functional group with an N or O is a H-bond acceptor.

N, O, and F

Question 16

What is an ion-dipole?

Answer 16

Very strong interaction between a full formal charge and a dipole.

Depends somewhat on the strength of the dipole

Question 17

What is an electrostatic interaction (ion-ion)?

Answer 17

Ionic interaction between cationic portion and anionic portion.

Effective at distances farther than other types of interactions.

Persist longer than other types of interactions.

Question 18

What are covalent bonds?

Answer 18

Strongest interaction, limited reversibility. Seldom formed.

Question 19

Name the intermolecular forces from #1 to #8

Answer 19

Question 20

Name the intermolecular forces from A to E

Answer 20