Chem Exam 1

Front 1

Difference between intermolecular & intramolecular forces?

Back 1

Intra forces are between atoms making up a compound, therefore stronger.

Inter forces determine physical properties & are forces between molecules

Front 2

Name the four intermolecular forces

Back 2

London dispersion, dipole-dipole, hydrogen bonding, ion-dipole

Front 3

Which intermolecular forces are also van der Waals forces?

Back 3

Dispersion, dip dip, hydrogen bonds

Front 4

All molecules have _____ forces

Back 4

London dispersion

Front 5

True/False: as molar mass increases, boiling point increases

Back 5

True

Front 6

Attraction between partially positive end of one molecule & partially negative end of neighboring molecule

Back 6

dip dip

Front 7

Strength of the pull (measure of polarity of the molecule)

Back 7

Dipole moment

Front 8

True/False: larger dipole moment = smaller boiling point

Back 8

False; dipole moment ⬆, boiling point⬆

Front 9

Attraction between hydrogen connected to O, N, F & non bonding e- pair on F, O, N atom

Back 9

Hydrogen bonding

Front 10

Does CH3COO have H bonding? Does CH3COOH?

Back 10

No; yes

Front 11

Coulombic attractions between ions (pos or negative) & polar molecules

Back 11

Ion-dip interaction

Front 12

When trying to put molecules in order of increasing/decreasing boiling point, what properties should you consider?

Back 12

Molar mass (⬆ MM = ⬆boiling point)

Strength of intermolecular forces (⬆strength = ⬆ boiling point)

Polarity (⬆ polarity = ⬆ boiling point)

Front 13

Rate the 3 physical states in order of increasing strength of attraction

Back 13

Gas, liquid, solid

Front 14

Amount of energy required to stretch/increase surface of a liquid by a unit area

Back 14

Surface tension

Front 15

Attraction between molecules and a surface

Back 15

Adhesion

Front 16

Forces among similar molecules

Back 16

Cohesion

Front 17

Water drawing up the walls of a glass container, making a CONVEX shape would be an example of

Back 17

Adhesion

Front 18

Mercury (Hg) staying away from the walls of a glass container, forming a concave shape, is an example of

Back 18

Cohesion

Front 19

Measure of a fluid's resistance to flow

Back 19

Viscosity

Front 20

____ intermolecular forces = higher viscosity.

Higher temp =______ viscosity

Larger molecule = _______ entanglement = ________ viscosity

Back 20

Stronger

Lower

More

Higher

Front 21

Which has higher viscosity & why?:

H2O or acetone (C3H6O)

Back 21

Water; has hydrogen bonding. Acetone only has dispersion

Front 22

Pressure exerted when liquid and vapor states are in equilibrium

Back 22

Vapor pressure

Front 23

Liquid molecules evaporate and gas molecules condense at same rate

Back 23

Dynamic equilibrium

Front 24

The faster a substance vaporizes, the more ____ it is

Back 24

Volatile

Front 25

Explains relationship between vap pressure and temp

Back 25

Clasius Clapeyron equation

Front 26

Amount of heat required to vaporize a mole of substance at its boiling point

Back 26

Molar heat of vaporization (∆Hvap)

Front 27

Amount of energy required to melt a mole of solid (go from solid to liquid)

Back 27

Molar heat of fusion (∆Hfus)

Front 28

∆H vap+ ∆H fusion =

Back 28

∆ H sublimation (solid to gas)

Front 29

Temperature at which various pressure = atmospheric pressure

Back 29

Boiling point

Front 30

Boiling point at 1 atm

Back 30

Normal boiling point

Front 31

Temp above which its gas cannot be liquefied

Back 31

Critical temp

Front 32

Minimum pressure needed to liquify a substance at its critical temp

Back 32

Critical pressure

Front 33

Combo of pressure and temp where 3 phases of a substance exist in equilibrium

Back 33

Triple point

Front 34

Substance at its critical temp and pressure exist as a gas and liquid

Back 34

Critical point

Front 35

Homogenous mix of 2+ pure substances; solute uniformly dispersed throughout solvent

Back 35

Solution

Front 36

Contains less solute than solvent and has capacity to dissolve at specific temp

Back 36

Unsaturated

Front 37

Max amount of solute that will dissolve in a solvent at a specific temp

Back 37

Saturated

Front 38

Amount of solute dissolved in a given volume of a saturated solution at a specific temp

Back 38

Solubility

Front 39

Contains more dissolved solute than is present in a saturated soln and are generally unstable

Back 39

Supersaturated

Front 40

Solute molecules separated from one another and surrounded by solvent molecules

Back 40

Solvation

Front 41

Endothermic or exothermic?:

Solute-solute

Solvent-solvent

Solute-solvent

Back 41

Usually endo

Usually endo

Usually exo

Front 42

What does it mean to be an electrolyte?

Back 42

If put in H2O, able to conduct electricity

Front 43

Substances with similar ____ tend to mix well together

Back 43

Polarity

Front 44

Mixing in all proportions

Back 44

Miscible

Front 45

Formula for mole fraction

Back 45

X sub a = moles of A/sum of moles of all components

Front 46

Molarity formula

Back 46

M= moles solute/Liters solution

Front 47

Molality formula

Back 47

m= moles solute/kg solvent

Front 48

Molarity is temp dependent or independent?

Back 48

Temp dependent

Front 49

Molality is temp dependent or independent?

Back 49

Independent

Front 50

Percent by mass formula?

Back 50

Mass solute/mass of solute + solvent (×100)

Front 51

Parts per million/billion?

Back 51

Mass solute/mass soln (x10^6/10^9)

Front 52

What 3 factors affect solubility?

Back 52

Structure, temperature & pressure

Front 53

How does structure affect solubility?

Back 53

Like substances dissolve like substances. If polarity not the same , dissolving minimal & solubility decreases

Front 54

In regards to solubility, what happens to gases when temperature increases?

Back 54

Solubility decreases

Front 55

For solid solutes in H2O, as temp increases, solubility

Back 55

Increases

Front 56

True or false: pressure has a tremendous impact on solubility in liquids and solids

Back 56

False; hardly affects them

Front 57

In gases, as pressure increases solubility

Back 57

Increases

Front 58

States that solubility of a gas in a liquid is proportional to pressure of gas over the solution

Back 58

Henry's Law

Front 59

The strongest intermolecular forces have the highest/lowest vapor pressure

Back 59

Lowest

Front 60

Properties that depend on # of solute particles in a solution

Back 60

Colligative properties

Front 61

Vapor pressure lowering, boiling point elevation, freezing point depression & osmotic pressure are examples of

Back 61

Colligative properties

Front 62

If a solution is ideal, this means that

Back 62

Intermolecular forces between molecules are similar

Front 63

Selective passage of solvent molecules thru a semipermeable membrane from a more dilute soln to more concentrated one

Back 63

Osmosis

Front 64

Pressure required to stop osmosis

Back 64

Osmotic pressure

Front 65

No net mvmt of H2O inside or out of cell

Back 65

Isotonic

Front 66

H2O moves into cell

Back 66

Hypotonic

Front 67

Tonicity; H2O moves out of cell

Back 67

Hypertonic

Front 68

Van't hoff factor

Back 68

i = actual # of particles in soln after dissociation/# of formula units initially dissolved in solution

Front 69

If dealing with non electrolyte, the Vant Hoff factor will be _____

If dealing with electrolyte, depends on _____ after dissociation

Back 69

1.

# of particles present

Front 70

Dispersion of particles of one substance to another substance

Back 70

Colloid

Front 71

Effect that showed particles are capable of scattering light

Back 71

Tyndall effect

Front 72

If a substance had a greater Van't Hoff factor relative to other substances, will it's freezing point highest or lowest?

Back 72

Lowest(think of it as more stuff that needs to be frozen so it takes more cooling)

Front 73

First Law of Thermodynamics states that

Back 73

E can neither be created nor destroyed, but transformed

Front 74

Occurs under a specific set of conditions without ongoing outside intervention... Exothermic processes are often this

Back 74

Spontaneous process

Front 75

Measure of how dispersed a system's energy is; represented by S

Back 75

Entropy

Front 76

Largest # of possible arrangement of molecules

Back 76

Most probable state

Front 77

Movement around an entire molecule from 1 place to another

Back 77

Translational

Front 78

Movement of a molecule around an axis or sigma bonds

Back 78

Rotational

Front 79

Periodic motion of atoms within a molecule

Back 79

Vibrational

Front 80

Which state has the largest entropy & why?

Back 80

Gas; has vibrational, transitional and rotational mvmt. Liquid has vibration with some t&r. Solid only has vibrational

Front 81

As Molar mass ⬆, Entropy...

Back 81

⬆

Front 82

As mobility ⬆, entropy ....

Back 82

⬆

Hint 82

Carbon diamond & graphite example

Front 83

As complexity ⬆, entropy ...

Back 83

⬆

Hint 83

O2 & O3. Think of # of bonds

Front 84

As temp ⬆, entropy...

As volume ⬆, entropy....

If rxn results in greater # of gas molecules, entropy....

With dissoln of a solute, with molecular solutes, entropy...

With ionic compounds, entropy...

Back 84

All⬆ except for ionic which is ⬆or ⬇

Front 85

Energy available to do work

Back 85

Gibbs free energy

Front 86

The entropy of a perfect crystalline substance at absolute 0 (0 K) is

Back 86

Zero