Ch 5: Solutions + Ch 6: Gases + Ch. 7 Liquids and Solids

Question 1

Units for pressure = ?

Answer 1

1 atm = 760 torr = 760 mmHg

Question 2

Gases behave more ideally under ___ pressure and ____ temperature

Answer 2

low pressure
high temperature
(this is stated by the ideal gas theory an kinetic molecular theory)
- at higher temperature collisions are more elastic and there will be no attraction among molecules

Question 3

What does the kinetic molecular theory state?

Answer 3

1. gas molecule do not have volume
2. there are no attraction forces between molecules
3. collisions are elastic = no intermolecular forces = no loss of energy
4. average kinetic energy depends on temperature

Question 4

What is the R gas constant?

Answer 4

8.3145 J/mol K

Question 5

What is avogadro’s law?

Answer 5

volume is proportional to moles

Question 6

Boyle’s law?

Answer 6

pressure is inversely proportional to volume

Question 7

Charles’ law?

Answer 7

volume is proportional to temperature

Question 8

Dalton’s law of partial pressure?

Answer 8

mix of gases, total pressure of mixture = summation of partial pressure of individual gases (molar fraction of gas times total pressure)

Question 9

Graham’s Law of Effusion

Answer 9

rate of effusion of a gas inversely proportional to square root of it’s molar mass

Question 10

___ bond are between tightly packed metal ions and a pool of electrons

Answer 10

metallic

Question 11

What forces hold liquids together?

Answer 11

intermolecular forces:

• van der waals
• dipole-dipole/polar
• hydrogen bonding

Question 12

A substance at very high temperature and pressure is at it’s

Answer 12

critical point.

= supercritical fluid with gaseous and liquid properties

Question 13

What is the freezing point depression formula?

Answer 13

dT freezing = i Kfreezing M

M = mol solute / mass of solvent

Question 14

If a type of solute is not important bt the van’t Hoff factor is important, what type of property is this?

Answer 14

colligative

Question 15

When two substances with different vapor pressures are combined, vapor pressure of mixture changes is according to who’s law?

Answer 15

Raoult’s law

P total = Pa + Pb

Question 16

Lower vapor pressure when adding salt in comparison to water.
Lower vapor pressure means fewer liquid particles vaporized.
This yields…

Answer 16

boiling point elevation

dt = iKboilingM

Question 17

What is sensible heat?

Answer 17

energy required to increase the temperature of a substance

Question 18

Rate of dissolution = rate of precipitation at…

Answer 18

molar solubility

solid form precipitated and dissolved form are at equilibrium

Question 19

For solids in liquids:

incr temperature means _____ solubility

Answer 19

increase solubility

Question 20

For gases in liquids:

incr temperature means ______ solubility

Answer 20

decrease solubility

Question 21

For gases in liquids:

increase pressure means ____

Answer 21

increase solubility

Question 22

Soluble or insoluble: CsOH

Answer 22

soluble

group 2 salts are always soluble

Question 23

Soluble or insoluble:

NH3NO2

Answer 23

soluble

nitrate, perchlorate, acetate are always soluble (think nitrate dissolving in nitrogen cycle

Question 24

Soluble or insoluble:

AgClO4

Answer 24

soluble

silver, lead, mercury is insoluble except with nitrates, perchlorates, acetates

Question 25

High vapor pressure means ____ intermolecular forces

Answer 25

weaker
therefore, substances will more easily evaporate
= more volatile

Question 26

What are the four properties of colligative properties?

Answer 26

1. Vapour pressure depression
2. Boiling Point elevation
3. Freezing point depression
4. Osmotic Pressure

Question 27

What is the difference between dissolution and solvation?

Answer 27

dissolution: solvent-solvent and solute-solute intermolecular attractions that need to be broken
solvation: solvent-solute intermolecular attractions that need to be formed to form a soluution

Question 28

What is stronger hydrogen bond or ion-dipole?

Answer 28

ion-dipole

-note hydrogen bond is a very strong type of dipole-dipole

Question 29

Intermolecular forces play a role in boiling points how so?

Answer 29

stronger intermolecular forces that hold molecules together, more energy required to separate i.e. boiling point is higher

Question 30

How do intermolecular forces play a role in determining solubility?

Answer 30

solute must be surrounded by solvent (solvated)

solute-solvent bonds stronger than > solute-solute or solvent-solvent bonds

Question 31

Boiling point: True or false

weaker intermolecular forces will have higher boiling point

Answer 31

False
stronger force = higher bp
need more energy to break strong force

Question 32

Boiling point: True or false

between nonpolar molecules the one with more extended molecule will have higher boiling point

Answer 32

True

as length of hydrocarbonds increase, boiling point and melting point increases

Question 33

Boiling point:

Do smaller or larger molecules have higher boiling points?

Answer 33

larger = higher bp