INTERMOLECULAR FORCES

Question 1

T/F The fundamental
difference between states
of matter is the strength of
the intermolecular forces
of attraction.

Answer 1

T

Question 2

they are referred to as the condensed phases

Answer 2

solids and liquids

Question 3

tendency of an electron cloud to distort

Answer 3

polarizability

Question 4

T/F If something is easier
to polarize, it has a
high boiling point.

Answer 4

F

Question 5

Polar molecules have a more positive and a more negative end–a dipole (two poles, δ + and δ).

Answer 5

dipole-dipole interactions

Question 6

strongest intermolecular force

Answer 6

hydrogen bonding

Question 7

The dipole–dipole interactions experienced when H is bonded to N, O, or F are unusually strong.

Answer 7

hydrogen bond

Question 8

interactions found in solutions of ions

Answer 8

ion-dipole interactions

Question 9

resistance of a liquid to flow

Answer 9

viscosity

Question 9

T/F Viscosity decreases with stronger
intermolecular forces and increases
with higher temperature.

Answer 9

F

Question 10

Water acts as if it
has a “skin” on it
due to extra inward
forces on its
surface.

Answer 10

surface tension

Question 11

Intermolecular forces that bind similar
molecules to one another

Answer 11

cohesive forces

Question 12

Intermolecular forces that bind a
substance to a surface

Answer 12

adhesive forces

Question 13

rise of liquids up narrow tubes

Answer 13

capillary actions

Question 14

T/F Water has stronger
adhesive forces with glass;
mercury has stronger
cohesive forces with itself.

Answer 14

T

Question 15

conversion from one state of matter to another

Answer 15

phase change

Question 16

the energy required to change a solid at its melting point to a liquid.

Answer 16

heat of fusion

Question 17

the energy required to change a liquid at its boiling point to a gas

Answer 17

heat of vaporization

Question 18

the energy required to change a solid directly to a gas

Answer 18

heat of sublimation

Question 19

a plot of temperature vs heat added

Answer 19

heating curve

Question 20

T/F gases solidify when pressure is applied

Answer 20

F

Question 21

The temperature beyond which a gas cannot be compressed

Answer 21

critical temperature

Question 22

the pressure needed to compress the liquid at critical temperature

Answer 22

critical pressure

Question 23

The normal boiling
point is the temperature at which
its vapor pressure

Answer 23

760 torr

Question 24

a graph of pressure vs. temperature for a substance.

Answer 24

phase diagram

Question 25

substances that do not go directly from the
solid state to the liquid state.

Answer 25

liquid crystals

Question 26

type of liquid crystals where molecules
are only ordered in
one dimension, along the long axis.

Answer 26

nematic liquid crystals

Question 27

type of liquid crystals where molecules are
ordered in two dimensions, along the long axis
and in layers.

Answer 27

smectic liquid crystals

Question 28

type of liquid crystals where nematic-like
crystals are layered at angles to each other.

Answer 28

cholesteryic liquid crystals

Question 29

T/F The stronger the Van der Waals forces, the
more energy is needed to break these forces
and the higher the boiling point.

Answer 29

T

Question 30

T/F As with boiling points, the melting points
of the alkanes increase with a decrease
in the number of carbon atoms.

Answer 30

F

Question 31

they have higher melting and boiling points than corresponding alkanes

Answer 31

alkylhalides

Question 32

they have boiling points similar to that of corresponding Aldehydes and Ketones

Answer 32

esters

Question 33

they have boiling points relatively higher than corresponding alcohols

Answer 33

carboxylic acids