Chem 2 Test 1

Front 1

What is diffusion?

Back 1

Process where particles of gases, liquids, or solids intermingle as a result of their kinetic properties

Front 2

what are intramolecular forces?

Back 2

Forces that cause atoms in a molecule to stay together

Front 3

What are intermolecular forces of attraction?

Back 3

forces that attract molecules together

Front 4

Are intermolecular forces or intramolecular forces greater?

Back 4

Intramolecular

Front 5

What is the definition of the boiling point of a substance

Back 5

The temperature at which sufficient energy is supplied to overcome the intermolecular forces

Front 6

How does intermolecular forces effect the boiling point of a substance?

Back 6

It increases the boiling point

Front 7

What are the 3 types of Intermolecular forces?

Back 7

London Dispersion

Dipole-induced dipole

Dipole-Dipole
-Hydrogen

Front 8

Are Ion Dipole forces intermolecular forces?

Back 8

No

Front 9

What is another name for london dispersion forces of attraction?

Back 9

induced dipole-induced dipole

Front 10

What has london dispersion forces?

Back 10

Everything

Front 11

What does polarizability mean?

Back 11

The ease with which the electron distribution in the species can be distorted. Generaly increases with # of electrons

Front 12

What intermolecular forces are present in non-polar molecules?

Back 12

only dispersion forces

Front 13

What happens to the melting point of a substance as the number of electrons in that substance increases

Back 13

melting point increases

Front 14

How do you convert celcius to kelvin?

Back 14

temp C + 273.15

Front 15

What is dipole dipole forces?

Back 15

attractive force between polar molecules?

Front 16

What type of intermolecular force is hydrogen bonding?

Back 16

dipole-dipole

Front 17

What elements can bond with hydrogen in a hydrogen bond?

Back 17

N,O,F

Front 18

What are charecteristics of N,O,F that make them want to bond with hydrogen in a hydrogen bond?

Back 18

2nd row elements
very small atoms
very electronegative
lone pairs of electrons in the hydride form

Front 19

What are all the intermolecular forces called together?

Back 19

Van der waals forces

Front 20

What kinds of intermolecular force happens between a polar molecule and a non-polar molecule?

Back 20

dipole induced dipole
and dispersion

Front 21

What kinds of intermolecular forces happens between two polar molecules

Back 21

dipole dipole and dispersion

Front 22

What kinds of intermolecular forces happen between two non-polar molecules?

Back 22

dispersion only

Front 23

Whats the definition of surface tension?

Back 23

amount of energy required to stretch or increase the surface of a liquid by a unit area

Front 24

Does surface tension increase or decease with higher intermolecular forces?

Back 24

increases

Front 25

Whats the diffrence between a waxed surface and an unwaxed surface and what do each of them due to a droplet of water on them?

Back 25

Waxed surface means no H bond and the droplet wants to minimize the surface area and therefor beads. With the unwaxed there are H-bonds and the droplet doesn't minimize its surface area.

Front 26

What is capillary action?

Back 26

the ability of a narrow tube to draw a liquid upwards against the force of gravity

Front 27

what forces cause capillary action?

Back 27

cohesion and adhesion

Front 28

what is cohesion and adhesion?

Back 28

cohesion is attraction between similary molecules
adhesion is attraction between a liquid and a solid
this is what causes water to rise in a tube.

Front 29

When refering to a straw in water. If adhesion is greater than cohesion will the water rise up in the straw or not?

Back 29

yes

Front 30

what is viscosity?

Back 30

measure of a fluids resistance to flow

Front 31

T/F the greater the viscosity the less freely a liquid flows.

Back 31

False the greater the viscosity the more slow the liquid flows

Front 32

What affects viscosity?

Back 32

Particle size
intermolecular forces
and temperature

Front 33

T/F the bigger the molecules the greater the viscosity?

Back 33

True

Front 34

T/F the greater the intermolecular forces the less the viscosity?

Back 34

False

Front 35

T/F the greater the temp, the lower the viscosity?

Back 35

True

Front 36

What is so unique about water in terms of surface tension, specific heat (amount of energy required to raise the temperatrue by 1C) and solid state relative to liquid state?

Back 36

Very high surface tension
High specific heat
solid is less dense than liquid

Front 37

What defines a crystalline solid?

Back 37

Rigid and long range order
sharp/well defined melting point

Front 38

What defines a amorphous solid?

Back 38

Lacks well defined arrangement and long range order

No sharp melting point

Front 39

What is a unit cell?

Back 39

basic repeating structural unit of a crystalline solid

Front 40

How many diffrent types of crystalline unit cells are there?

Back 40

7

Front 41

What are the 3 types of cubic cells, how many particles do each have, and where are the particles located for each?

Back 41

simple cubic- 8 particles located at each corner of the cube

body-centered cubic- 9 particles 8 on corners and 1 in the middle

face-centered cubic- 12 particles, 8 in the corners and 1 more on each face (6 total)

Front 42

How many atoms per unit cell are there for the 3 main cubic cells (simple, body centered, face centered)?

Back 42

simple-((1/8)*8)=1 atom

body centered-((1/8)*8+1(center))=2 atoms

face centered-((1/8)*8+(1/2)*6)=4 atoms

Front 43

What is a coordination number? and what is the coordination number of the 3 main cubic cells?

Back 43

the number of atoms or ions surrounding an atom or ion in a crystal lattice

simple- 6

body centered- 8

face centered- 12

Front 44

How many atoms in a simple cubeic cubic cell?

Back 44

6

Front 45

How many atoms in a face centered cubic?

Back 45

12

Front 46

How many atoms in a body centered cubic?

Back 46

8

Front 47

When silver crystallizes, it forms face centered cubic cells. The unit cell edge length is 409pm. Calculate the density of silver.

Back 47

10.5

Front 48

Bragg equation: n (lamda) = 2dsin (theta) what does everythign mean

Back 48

lamda=wavelength
d=distance between adjacent planes in the crystal
theta=angle between x rays and plane of crystal

Front 49

X rays of wavelength 0.154 nm (0.154 x 10-9 m) are diffracted from a crystal at an angle of 14.170. Assuming that n = 1, what is the distance in nm between layers in the crystal?

Back 49

0.315 nm

Front 50

What are the 4 types of crystals?

Back 50

Ionic
Covalent
Molecular
Metallic

Front 51

What are some characteristics of ionic crystals?

Back 51

Lattice points occupied by charged species (cations and anions) held together by ionic bonds
High melting points, hard, brittle
Poor conductor of heat and electricity (ions are fixed in positions)
Examples:
Note: Anions are much larger than cations

Front 52

What are some characteristics of covalent crystals?

Back 52

Lattice points occupied by atoms held together by covalent bonds
High melting point, hard
Poor conductor of heat and electricity
Examples: diamond (C), graphite (C), quartz (SiO2), silicon carbide (SiC)

Front 53

What are some characteristics of molecular crystals?

Back 53

Lattice points occupied by molecules held together by intermolecular forces (weaker than ionic or covalent bonds)
Low melting point, soft
Poor conductor of heat and electricity
Examples:
so2,I2,H2O,CH4

Front 54

What are some characteristics of metallic crystals?

Back 54

Lattice points occupied by metal atoms held together by metallic bonds
Low to high melting point, Soft to hard
Good conductors of heat and electricity
Examples: Mg, Ni, Sn, Cs

Front 55

What phase has the greatest molecular order?

Back 55

solid phase

Front 56

What is dynamic equilibrium?

Back 56

when the rates of condensation and evaporation are equal

Front 57

What is equilibrium vapor pressure?

Back 57

vapor pressure when a dynamic equilibrium exists

Front 58

What is molar heat of evaporation and what is the symbol?

Back 58

energy required to vaporize 1 mole of liquid
change Hvap

Front 59

What is the exact definition of boiling point?

Back 59

when the temp at which the vapor pressure of a liquid is equal to the external pressure

Front 60

How does change in heat vaporization coerlate with boiling point?

Back 60

higher the Hvap the higher the boiling point

Front 61

Name all the variables in the following equation and what the equation could be used to find:
lnP=-(chng Hvap/RT)+C

Back 61

P=Equilibrium vapor pressure
T=temp
R=gas constant (8.314)

Front 62

What is critical temperature?

Back 62

temp above which the gas cannot be made to liquify

Front 63

what is critical pressure (Pc)

Back 63

min pressure that must be applied to liquify a gas at Tc

Front 64

What is molar heat of fusion?

Back 64

energy required to melt 1 mole of a solid, chng Hfus
its the temp at which solid and liquid coexist icewater

Front 65

Is chngHvap>chngHfus?

Back 65

yes

Front 66

What is sublimation?

Back 66

when solid goes directly to gas

Front 67

what is molar heat of sublimation?

Back 67

energy required to sublime 1 mole of a solid
chngHsub
chngHsub=chngHfus+chngHvap

Front 68

What three things are factors that influence the ease at which a solute will dissolve?

Back 68

solvent-solvent interaction
solute solute interaction
solvent solute interaction

Front 69

What is entropy?

Back 69

inherent tendency toward disorder and intermingling

Front 70

chngHsoln=?

Back 70

=chngHsolv+chngHsolute+chngHmixing

Front 71

what is soluability and what are the units?

Back 71

measure of how much solute will dissolve in a solvent at a specific temp
mol solute/liter solution or
grams solute/100grams solvent

Front 72

what is miscibility?

Back 72

ability for two liquids to be compleatly soluble in each other

Front 73

What kinds of substances are likely to be soluble in one another?

Back 73

like substances - ones with similar intermolecular forces

Front 74

What are the 4 types of concentration units?

Back 74

percent by mass
mole fraction
Molarity
Molality

Front 75

Give the equation and units for the concentration unit of:
Percent by Mass

Back 75

% by mass =mass solute/(mass solute+ mass solvent)

Front 76

Give the equation and units for the concentration unit of:
Mole Fraction (X)

Back 76

X=moles of A/(sum of moles of all compounds)

Front 77

Give the equation and units for the concentration unit of:
Molarity (M)

Back 77

M = moles solute/liters solution

Front 78

Give the equation and units for the concentration unit of:
Molality(m)

Back 78

m=moles solute/mass of solvent(kg)

Front 79

What is the molality of a 5.86 M ethanol (C2H5OH) solution whose density is 0.927 g/mL?

Back 79

8.92 m

Front 80

T/F does the soluability of a solid increase with temp?
T/F does the soluability of a gas increase with temp?

Back 80

True for solid

False for gas

Front 81

Solution of 16.0 g MgSO4 and 100 mL of H2O at 25 °C. What is the mole fraction of each component?
dH2O at 25 °C = 0.997 g/mL
MWMgSO4 = 120.4 g/mol
MWH2O = 18.0 g/mol

Back 81

(X)MgSO4=0.0235
(X)H2O=0.977

Front 82

What is Henry's Law and what do the variables mean?

Back 82

c=kP
c=concentration M of the dissolved cas
P=pressure of gas over solution
k=constant that depends on temp

Front 83

The concentration of dissolved oxygen in an aqueous solution is 0.44g / 0.1 L solution.
The partial pressure of oxygen above the solution is 150 mm Hg.
What is the predicted oxygen concentration (in g/100 mL) if the partial pressure for oxygen is reduced to 56 mm Hg?

Back 83

c2=0.164 g/ml

Front 84

What are teh 4 colligative properties?

Back 84

vapor pressure lowering
boiling point elevation
freezing point depression
osmotic pressure

Front 85

What is Raoult's Law what does it refer to and what are the units and variables?

Back 85

Psoln=Xsolvent*P'solvent
Psoln=vapor pressure of solution
Xsolvent=mole fraction for solvent
P'solvent=vapor pressure of the pure solvent

Front 86

What is the vapor pressure at 25 ºC of an aqueous sucrose (C12H22O11) nonvolatile solution that contains 300 g sucrose dissolved in 1000 g water ?
Pºwater = 23.76 torr

Back 86

23.39 torr

Front 87

What is the vapor pressure of a solution at 20 ºC that contains water (H2O) and ethanol (C2H5OH) (0.60 mole fraction H2O and 0.40 mole fraction C2H5OH) ?

V.P. of H2O = 17.5 torr at 20 ºC
V.P. of C2H5OH = 44.0 torr at 20 ºC

Back 87

Ptotal=28.1 torr

Front 88

What is the equation for boiling point elevation?

Back 88

ΔTb = (Tb – T°b ) = Kbm
ΔTb = b.p. increase
Kb = b.p. elevation constant
m=molality of solute particles

Front 89

What is the equation for freezing point depression?

Back 89

ΔTf = (T°f – Tf ) = Kfm
ΔTf = f.p. decrease
Kf = f.p. decrease
m = molality of the solute particles

Front 90

What is the freezing point of a solution containing 478 g of ethylene glycol (antifreeze) in 3202 g of water? The molar mass of ethylene glycol is 62.01 g.
chngTf = Kf m
Kf water = 1.86 0C/m

Back 90

-4.48 degrees C

Front 91

what is osmosis?

Back 91

The selective passage of solvent molecules through a porous membrane from a dilute solution to a more concentrated one

Front 92

What is the equation for osmotic pressure (π)?

Back 92

π = MRT
M =Molarity of solution
R = ideal gas constant (0.0821 L.atm/mol.K)
T = Kelvin temperature (absolute T)

Front 93

What is the diffrence between electrolyte and nonelectrolyte?

Back 93

non-electrolytic has one mole to one mole of solid = one mole particles in solution
electrolytic is one mole solid = more than one mole particles in solution

Front 94

What is van't hoff factor(i) in terms of electrolytic solutions?

Back 94

van’t Hoff factor (i) =
actual number of particles in sol’n after dissociation/
number of formula units initially dissolved in sol’n

Front 95

when doing boiling point elevation for electrolytic solutions what do we multiply kfm and kbm by?

Back 95

i which = # particles in solution after/# particles before