exam 1

Question 1

intermolecular forces

Answer 1

attractive forces that hold particles together

Question 2

Dispersion

Answer 2

Temporary polarity in the molecules due to unequal (shifting) electron distribution

Question 3

Dipole–dipole

Answer 3

Permanent polarity in the
molecules due to their structure

Question 4

Ion-dipole

Answer 4

the electrostatic attraction between an ion (a charged particle) and a polar molecule

Question 5

hydrogen bonds

Answer 5

especially strong dipole-dipole attraction when H is attached to an extremely electronegative atom.

N, O, F

Question 6

Surface tension

Answer 6

the tendency of liquid surfaces to shrink into the minimum surface area possible

Question 7

Viscosity

Answer 7

Resistance of a liquid to flow.
for example honey has a high viscosity

Question 8

Capillary action

Answer 8

the ability of a liquid to flow up a thin tube against the influence of gravity.

Question 9

what causes capillary action

Answer 9

The adhesive forces pull the surface liquid up the side of the tube, and the cohesive forces together the interior liquid

Question 10

Vaporization

Answer 10

phase change from liquid to gas because it has enough kinetic energy to escape the surface

Question 11

Vapor pressure

Answer 11

The pressure exerted by the vapor when it is in dynamic equilibrium

Question 12

Sublimation

Answer 12

phase change from solid to gas

Question 13

Phase change

Answer 13

physical change
transformation of a substance from one state of matter to another due to changes in pressure and temp

Question 14

Phase diagram

Answer 14

summarizes the conditions at which a
substance exists as a solid, liquid, or gas

Question 15

Triple point

Answer 15

combination of pressure and temperature where three phases of a substance exist in equilibrium

Question 16

Critical point

Answer 16

represents the pressure and temperature above which a supercritical fluid exists

found at the tip of the line between liquid and vapor

Question 17

Phase boundary

Answer 17

line where 2 phases of matter exist at equilibrium

Question 18

what causes intermolecular forces

Answer 18

the interactions between charges, partial charges, and temporary charges on molecules

Question 19

4 types of intermolecular forces

Answer 19

1. london dispersion forces
2. dipole-dipole forces
3. hydrogen bonding
4. ion dipole forces

Question 20

how do weaker attractive forces affect vapor pressure

Answer 20

weaker attractive forces=higher vapor pressure=more volatile liquid

strong attractions make it harder for liquid molecules to escape into the gas phase

Question 21

how do intermolecular forces affect boiling point

Answer 21

weaker attractive forces=lower boiling point

Question 22

volatile liquids

Answer 22

vaporize faster

Question 23

vapor pressure vs vaporization

Answer 23

lower vapor pressure=higher vaporization

low vapor pressure, fewer molecules are in the vapor phase → liquid molecules can easily escape → vaporization is faster.

Question 24

dynamic equilibrium vs condensation

Answer 24

Once equilibrium is reached, vaporization still occurs, but at the same rate as condensation → no net change in liquid amount.

Question 25

vapor pressure vs temp

Answer 25

inc temp=inc vapor pressure

Question 26

crystalline

Answer 26

a solid in which molecules are arranged in repeating patterns

Question 27

Amorphous

Answer 27

a solid in which molecules are not arranged in a pattern

Question 28

X-ray diffraction

Answer 28

using x-ray to determine diffraction pattern which is based on constructive and obstructive interference with the x-ray

Question 29

Crystalline lattice

Answer 29

arrangement of atoms in a crystalline solid

Question 30

Unit cell

Answer 30

smallest unit that shows pattern arrangement for crystal lattice

Question 31

Molecular Solid

Answer 31

crystalline solid made of molecules weak attractive forces--> low boiling point

Question 32

Ionic solid

Answer 32

a crystalline solid made of ions strong attractive forces because of charges--> high boiling point

Question 33

Graphite

Answer 33

hexagonal layers of sp2 carbons

Question 34

Atomic solid

Answer 34

crystalline solid made of atoms nonbonding atomic solids, metallic atomic solids, and network covalent solids

Question 35

Diamond

Answer 35

3-D tetrahedral sp3 carbons

Question 35

Graphene

Answer 35

single layer of hexagonal sp2 carbon

Question 36

Polymer

Answer 36

A long chain-like molecule composed of many repeating units typically organic

Question 37

nonbonding atomic solid

Answer 37

An atomic solid held together by dispersion forces low melting point ex: argon, xenon

Question 38

metallic atomic solid

Answer 38

An atomic solid held together by metallic bonds ex: iron, gold, copper

Question 39

network covalent atomic solid

Answer 39

An atomic solid held together by covalent bonds high melting point ex: diamond, graphite, SiO2

Question 40

what constitues the majority of earths crust

Answer 40

silicon and oxygen

Question 41

solute

Answer 41

component being dissolved in a solution

Question 42

solvent

Answer 42

major component of a solution, usually water

Question 43

solution

Answer 43

homogeneous mixture of two or more substances

Question 44

saturated

Answer 44

A solution that has the solute and solvent in dynamic equilibrium

Question 45

unsaturated

Answer 45

A solution that has less solute than saturation

Question 46

super saturated

Answer 46

A solution that has more solute than saturation i

Question 47

equilibrium

Answer 47

rate of dissolution = the rate of deposition rate of the reverse reaction=rate of the forward reaction

Question 48

solubility

Answer 48

The amount of a substance that will dissolve in a given amount of solvent

Question 49

miscible

Answer 49

The ability of two or more substances to be soluble in each other in all proportions

Question 50

solvation

Answer 50

when solute molecules are separated from one another and surrounded by solvent molecules

Question 51

molality

Answer 51

expressing solution concentration as the number of moles of solute per kilogram of solvent mol solute/kg solvent

Question 52

molarity

Answer 52

expressing solution concentration as the number of moles of solute per liter of solution mol solute/L solution

Question 53

mole fraction

Answer 53

solute (mol)/total amt solute+solvent

Question 54

parts by mass

Answer 54

(solute mass/solution mass)x(multiplication factor 10^x)

Question 55

percent by mass

Answer 55

(mass solute/mass solute+solvent)x(100)

Question 56

colligative property

Answer 56

depend only on the number of solute particles in a solution, not type

Question 57

osmosis

Answer 57

The flow of solvent from a solution of lower solute concentration to one of higher solute concentration

Question 58

van’t Hoff factor

Answer 58

i=moles of particles in solution/moles of formula units dissolved Non-electrolyte: i=1 NaCl: i=2 CaCl2: i=3

Question 59

ΔTf​ (Freezing point depression)

Answer 59

iKf​m i=van't hoff Kf=freezing point m=molality

Question 60

Tf (Freezing point of solution)

Answer 60

freezing point solvent-ΔTf​

Question 61

ΔTb​ (Boiling point elevation)

Answer 61

iKb​m i=van't hoff Kb=boiling point m=molality

Question 62

Tb

Answer 62

boiling point solvent+ΔTb​

Question 63

what leads to higher osmotic pressure

Answer 63

higher i value