Exam 1

Question 1

melting

Answer 1

solid to a liquid

Question 2

freezing

Answer 2

liquid to a solid

Question 3

Sublimation

Answer 3

solid to a gas

Question 4

condensation

Answer 4

gas to a liquid

Question 5

What do changes of state require

Answer 5

energy

Question 6

true or false: does the reverse process of changing states require more energy

Answer 6

false, it requires the same amount of energy

Question 7

What kind of solution will a nonpolar (or mostly nonpolar) compound dissolve in?

Answer 7

nonpolar solutions (ex: vitamin A)

Question 8

What kind of solution will a polar (or mostly polar) compound dissolve in?

Answer 8

polar solutions (ex: vitamin C)

Question 9

miscible

Answer 9

things will mix and form a homogeneous solution (“like” forces)

Question 10

immiscible

Answer 10

don’t mix and will form a heterogeneous solution, “layers” (“not like “ forces)

Question 11

What is behind things being miscible or immiscible?

Answer 11

Intermolecular forces (IMFs)

Question 12

What effect do IMFs have on properties?

Answer 12

1. increases boiling point
2. increases melting points
3. fusion, vaporization, and sublimation will be larger
4. higher surface tension
5. lower vapor pressure

Question 13

What is an instantaneous dipole?

Answer 13

electrons being on the same side

Question 14

Dispersion force

Answer 14

a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles

Question 15

True or False: More electrons mean a higher dispersion force

Answer 15

True

Question 16

What else is a Dipole-Dipole interaction known as?

Answer 16

Polar-Polar interaction

Question 17

True or False: More Polar means a stronger dipole-dipole moment?

Answer 17

True

Question 18

In dipole-dipole interactions what is the positive end of a polar molecule attracted to?

Answer 18

A positive end of a polar molecule is attracted to the negative end of its neighbor

Question 19

True or False: hydrogen bonding is a dipole-dipole subset

Answer 19

True

Question 20

Hydrogen bonding is a type of dipole-dipole interaction, NOT what?

Answer 20

it is NOT a covalent bond to a hydrogen atom

Question 21

Why is hydrogen bonding only with Nitrogen, Oxygen, and Fluorine?

Answer 21

It only involves nitrogen, oxygen, or fluorine atoms because these atoms have high electronegativity. Since they have very high electronegativity, these three atoms can easily attract the electron found in the hydrogen atom and form hydrogen bonds.

A clever way to remember that hydrogen bonds only occur with these molecules is, “hydrogen bonding is FON(fun).”

Question 22

Which IMF is only present in solutions (mixtures of ionic and polar compounds) and not pure substances?

Answer 22

Ion-Dipole

Question 23

In Ion-dipole forces what is the positively charged end of a polar molecule attracted too? and what is the negatively charged end of a molecule attracted to?

Answer 23

the positively charged end of a polar molecule is attracted to negative ions and the negatively charged end is attracted to positive ions

Question 24

Where would dispersion forces be present in?

Answer 24

all molecules and atoms

Question 25

Where would dipole-dipole be present in?

Answer 25

polar molecules

Question 26

Where would hydrogen bonding be present in?

Answer 26

molecules containing H bonded to F,O, or N

Question 27

Where would ion-dipole be present in?

Answer 27

mixtures of ionic and polar compounds

Question 28

IMFs from strongest to weakest

Answer 28

1. Ion-dipole 2. Hydrogen bonding 3. dipole- dipole 4. Dispersion

Question 29

What molecules may have enough energy to overcome the attractive forces?

Answer 29

High-energy molecules

Question 30

True or False: The larger the surface area, the faster the rate of evaporation

Answer 30

true

Question 31

What is Dynamic equilibrium?

Answer 31

rate of evaporation = rate of condensation

Question 32

True or false: small changes in temperature don't make any changes in vapor pressure

Answer 32

FALSE, small changes in temperature can make BIG changes in vapor pressure

Question 33

Surface tension

Answer 33

the amount of energy required to overcome the attraction of other molecules at the surface of a liquid

Question 34

viscosity

Answer 34

the resistance of a liquid to flow

Question 35

What do larger intermolecular attractions equal?

Answer 35

larger viscosity (more viscous) because stronger IMFs slow down molecules and will lead to slower liquid flow

Question 36

capillary action

Answer 36

the ability of a liquid to flow up a thin tube against the influence of gravity (the narrower the tube, the higher the liquid rises)

Question 37

adhesion

Answer 37

force of attraction existing between different molecules

Question 38

cohesion

Answer 38

forces existing between two same molecules

Question 39

In phase diagrams what do the lines mean?

Answer 39

lines represent changes, and on the line both phases exist simultaneously

Question 40

What is the critical point on a phase diagram?

Answer 40

it is the furthest point on the vapor pressure curve; it's where it breaks down liquid and gas barrier

Question 41

What is the triple point?

Answer 41

the temperature/pressure condition in which all three states exist simultaneously

Question 42

What is a dipole-induced dipole

Answer 42

an atom with a permanent charge can induce a dipole (dipole = polar molecule) (same thing for dispersion but instead of charge it's the prominent dipole)

Question 43

Which IMFs can be present in pure substances?

Answer 43

1. dispersion 2. dipole-dipole 3. hydrogen bonding

Question 44

Which IMFs can ONLY be present in mixtures?

Answer 44

1. ion-induced dipole 2. dipole-induced dipole 3. ion-dipole

Question 45

** A type of question that would be on the test** Which of the following pairs is likely to form a homogeneous mixture? a.) LiI and Hg b.) C6H14 and Br2 c.) CH3OH and C6H6 d.) CCl4 and H2O e.) all pairs above are miscible

Answer 45

b.) C6H14 and Br2 because both are nonpolar

Question 46

Saturated solution

Answer 46

solvent holds as much solute as is possible at that temperature (Undissolved solid may be present)

Question 47

Unsaturated solution

Answer 47

less than the maximum amount of solute for that temperature is dissolved in the solvent (below solubility limit)

Question 48

Supersaturated solution

Answer 48

solvent holds more solute than is normally possible at that temperature (above the solubility limit; beyond the max amount we can have in a solution)

Question 49

How can a super-saturated solution be made to precipitate out?

Answer 49

1. adding more solute 2. agitating the solution

Question 50

When does the solubility of solid solutes in liquid solvents increase?

Answer 50

with increasing temperature

Question 51

What does being on the curve in a solubility curve=

Answer 51

saturated

Question 52

What does being below the curve in a solubility curve=

Answer 52

unsaturated

Question 53

What does being above the curve in a solubility curve=

Answer 53

supersaturated

Question 54

What happens to gas solubility with increasing temperature

Answer 54

Gas solubility DECREASES with increasing temperature

Question 55

When are gases most soluble?

Answer 55

low temperature and high pressure

Question 56

The warmer the liquid..?

Answer 56

the less gas will be dissolved

Question 57

In general what happens to the solubility of gases in water?

Answer 57

the solubility of gases in water increases with increasing mass

Question 58

Larger molecules have stronger what?

Answer 58

larger molecules have stronger London Dispersion Forces

Question 59

What is the solubility of a gas in a liquid directly proportional to?

Answer 59

its pressure

Question 60

What is Henry's Law formula?

Answer 60

Sg=KhPg

Question 61

What does the Sg represent in Henry's law formula?

Answer 61

solubility of gas

Question 62

What does the k represent in Henry's law formula?

Answer 62

henry's law constant for that gas in that solvent (constant at a given temp only)

Question 63

What does the Pg represent in Henry's law formula?

Answer 63

the partial pressure of the gas above the liquid

Question 64

Molarity=?

Answer 64

amount of solute (in mol) / volume of solution (in L)

Question 65

Molality=?

Answer 65

amount of solute (in mol) / mass solvent (in kg)

Question 66

What do changes in physical properties depend on?

Answer 66

Changes in physical properties depend only on the number of solute particles present, NOT on the identity of the solute particles

Question 67

What is the symbol for Van Hoff factor?

Answer 67

i

Question 68

When solute concentration goes up, what happens to the following colligative properties? 1. vapor pressure 2. boiling point 3. freezing point 4. osmotic pressure

Answer 68

1. vapor pressure LOWERS 2. boiling point INCREASES 3. freezing point DECREASES 4. osmotic pressure INCREASES

Question 69

osmosis

Answer 69

movement of solvent from an area of low concentration to an area of high concentration

Question 70

Isotonic solution

Answer 70

solution that contains the same amount of solute and water concentration (normal red blood cells)

Question 71

Hypertonic solution

Answer 71

high solute concentration and low water concentration (flows from the outside in/ shriveled red blood cells)

Question 72

Hypotonic solution

Answer 72

low solute concentration and high water concentration (flows from the outside in / swollen red cells)

Question 73

osmotic pressure

Answer 73

the pressure required to stop osmosis

Question 74

what is the formula for osmotic pressure?

Answer 74

pi=MRT or pi=iMRT

Question 75

The higher the solute concentration, the higher the what?

Answer 75

the higher the osmotic pressure of the solution

Question 76

What is the normal freezing point of water?

Answer 76

0 degrees celsius

Question 77

What is the normal boiling point of water?

Answer 77

100 degrees Celsius

Question 78

As the concentration (molality) of solute particles increases, what happens to the freezing and boiling point?

Answer 78

the FREEZING point decreases, and the BOILING point increases

Question 79

volatile

Answer 79

substances that readily vaporize liquids

Question 80

The weaker the IMF's, the higher the vapor pressure and ....

Answer 80

the more volatile the compound and the lower the normal boiling point

Question 81

True or false: the vapor pressure of solution will always be lower than vapor pressure of the solvent

Answer 81

true

Question 82

What factors affect rates?

Answer 82

1. physical state 2. reactant concentration 3. reaction temperature 4. catalysts

Question 83

What is the equation that can be used to find the new freezing point?

Answer 83

delta T= miK

Question 84

What is Raoult's law mole fraction?

Answer 84

mol of solvent / total moles

Question 85

What does a zero-order graph look like?

Answer 85

It is descending left to right and the y axis says [A]

Question 86

What does a first-order graph look like?

Answer 86

it is descending from left to right and the y-axis says ln[A]

Question 87

What does a second-order graph look like?

Answer 87

It is ascending from left to right and the y-axis says 1/[A]

Question 88

What does the zero-order rate law look like?

Answer 88

[A]t=-kt+[A]0

Question 89

What does the first-order rate law look like?

Answer 89

ln[A]t=-kt+ln[A]0

Question 90

What does the second-order rate law look like?

Answer 90

1/[A]t=kt+1/[A]0

Question 91

The same reaction is run at 25 degrees Celsius and 50 degrees Celsius. Which statement is always true? a) The rate constant at 50 degrees will be twice as fast as the rate constant at 25 b) The rate constant will be greater at 25 c) The rate constant will be greater at 50 d) The rate constant will be the same at both temperatures

Answer 91

c) The rate constant will be greater at 50 because higher temperature, so rate constant will be greater

Question 92

What is an Elementary reaction

Answer 92

reaction resulting from a single collision of molecules/atoms

Question 93

Molecularity

Answer 93

The number of molecules/atoms involved in a single step

Question 94

The lower the molecularity..the what?

Answer 94

the more likely it is for a single collision to occur

Question 95

What is the 1st order Integrated Rate Law equation

Answer 95

ln [A]t / [A]0 = -kt

Question 96

what is the formula for mass percent?

Answer 96

mass of solute / mass of solution * 100