Unit 3: Intermolecular Forces and Properties

Question 1

Polar Covalent Bond

Answer 1

Unequal sharing of electrons

Question 2

Dipole

Answer 2

A pair of opposite electric charges separated by some distance, represented by δ and a positive or negative charge

Question 3

Intermolecular forces (IMFs)

Answer 3

Forces that exist between molecules in a covalently bonded substance

Question 4

Dipole-Dipole Forces

Answer 4

Occur between polar molecules

Question 5

Dipole Moments

Answer 5

The measurement of strength of electrical dipoles

Question 6

Hydrogen Bonds

Answer 6

Type of dipole-dipole bond, the positively charged hydrogen end of a molecule is attracted to the negatively charged end of another molecule containing an extremely electronegative element (fluorine, oxygen, or nitrogen)

Question 7

London Dispersion Forces (LDFs)

Answer 7

Occurs between all molecules. At a given moment, a nonpolar molecule might have more electrons on one side than on the other, giving it an instantaneous polarity

Question 8

Polarizability

Answer 8

The tendency of a substance to form dipole moment

Question 9

Vapor Pressure

Answer 9

When molecules hit the surface of the liquid with enough kinetic energy to escape the intermolecular forces holding them to the other molecules and transition into the gas phase (no outside energy needs to be added)

Question 10

Dissociation

Answer 10

When an ionic substance disolves and breaks up into ions

Question 11

Electrolytes

Answer 11

Free ions in a solution that can conduct electricity

Question 12

Chromatography

Answer 12

The separation of a mixture by passing it in solution through a medium in which the components of the solution move at different rates

Question 13

Rf Value

Answer 13

(Distance traveled by solute)/(Distance traveled by solvent front)

Question 14

Analyte

Answer 14

The solution that is being separated in chromatography

Question 15

Eluent

Answer 15

The second solution that is added in chromatography

Question 16

Effusion

Answer 16

The rate at which a gas will escape from a container through microscopic holes in the surface of the container (from an area of high pressure to one of low pressure)

Question 17

Spectrophotometer

Answer 17

Measures the amount of light at a given wavelength that is absorbed by a solution

Question 18

Colorimeter

Answer 18

A spectrophotometer that can only emit light at specific frequencies