Chapter 11

Question 1

How do the densities of gas liquids and solids compare?

Answer 1

Gas has the least density

Then solid then liquid

Question 2

How does the volume of a gas liquid and solid compare?

Answer 2

Gas has most volume then solid and then liquid

Question 3

What are the two ways states of matter can be changed?

Answer 3

Changing the temperature and/or the pressure

Question 4

What are London dispersion forces?

Answer 4

The result in changes of electron distribution (since all atoms have electrons they all exhibit dispersion forces)

Question 5

How can we determine the magnitude of dispersion forces?

Answer 5

Using molar mass- higher molar mass= higher boiling point= greater forces
Using shape of molecule too

Question 6

What is a dipole-dipole Force?

Answer 6

Exists in all molecules that are polar

Question 7

How do the boiling points of polar molecules compare to non polar molecules of similar mass?

Answer 7

Polar molecules have higher boiling points since they have dipole dipole forces

Question 8

What is miscibility?

Answer 8

The ability to mix without separating into two phases

Polar molecules are miscible with other polar molecules but not non polar ones

Question 9

What is hydrogen bonding?

Answer 9

They are polar molecules containing hydrogen atoms bonded directly to small electronegative atoms
(Sort of super dipole-dipole bond)

H-F
H-O
H-N

Question 10

What’s the difference between intermolecular and intramolecular?

Answer 10

Inter- between molecules H-F

Intra- chemical bonds within molecules

Question 11

What is an ion dipole Force?

Answer 11

Occurs when an ionic compound is mixed with a polar compound
NaCl + H2O

Question 12

What are the strengths of the following bonds in order of least strongest to strongest?
Ion-dipole
Hydrogen bonding
London dispersion forces
Dipole-dipole

Answer 12

Weakest
Dispersion
Dipole-dipole
Hydrogen bonding
Ion-dipole
Strongest

Question 13

What is surface tension? How is it affected by intermolecular forces?

Answer 13

The energy required to increase the surface area by a unit amount

Decreases with decreasing intermolecular forces

Question 14

What is viscosity? How is it affected by intermolecular forces?

Answer 14

The resistance of a liquid to flow

It is greater in substances with stronger intermolecular forces

Question 15

What is vaporization? Exothermic or endothermic?

Answer 15

Going from liquid to gas

Endothermic

Question 16

What is condensation? Exothermic or endothermic?

Answer 16

Gas to liquid

Exothermic

Question 17

What does volatile mean?

Answer 17

Liquids that vapourize easily are volatile

Question 18

What is the heat of vaporization? What’s the sign for condensation?
What’s the sign for vaporization?

Answer 18

The amount of heat required to vaporize one mole of a liquid to gas

ΔHvap

Condensation is negative sine it’s exothermic
Vaporization is positive since it’s endothermic

Question 19

How does water act in a sealed container?

Answer 19

Dynamic equilibrium occurs where the rate of evaporation is equal to the rate of condensation

Question 20

What is the vapour pressure of a liquid? How do intermolecular forces affect this?

Answer 20

The pressure of a gas in dynamic equilibrium with its liquid

Weak intermolecular forces= higher vapor pressure

Question 21

What is he boiling point of a liquid?

Answer 21

The temperature at which it’s vapor pressure equals the external pressure

Question 22

What is the normal boiling point of a liquid?

Answer 22

The temperature at which it’s vapor pressure equals 1 atm

Question 23

What is sublimation?

Answer 23

Going from solid to gas

Question 24

What is deposition?

Answer 24

Gas to solid

Question 25

What is fusion? What is the heat of fusion? Endothermic or exothermic?

Answer 25

Melting (solid to liquid)

ΔHfus= the amount of heat required to melt 1 mol of a solid
Positive since it’s endothermic

Question 26

What is the triple point?

Answer 26

Represents the unique conditions at which three states are equally stable and in equilibrium (all three states at once)

Question 27

What is the critical point?

Answer 27

Represents the temperature and pressure above which a supercritical fluid exists