Solutions

Question 1

dipole:

Answer 1

a polar bond

Question 2

dipole moment

Answer 2

the arrow thing represents the polarity of the dipole (points toward the partially positive side)

Question 3

net dipole

Answer 3

the sum of bond dipoles in three dimensions

Question 4

intermolecular

Answer 4

between 2 different molecules (IMF is between molecules of the same compound)

Question 5

intramolecular

Answer 5

within a molecule (ie bonds)

Question 6

intermolecular force

Answer 6

aka IMF; the attractive force between 2 molecules; significantly weaker than covalent bonds

Question 7

london dispersion force

Answer 7

when molecules move/collide, there can be momentary shifts in their e-clouds, which is when the molecules can have a dipole that can experience dipole-dipole (only in the moment of collision)
- larger molecules have ↑ LDF (a large e-cloud can shift more b/ more “polarizable”)
- larger surface areas are also more polarizable (so connect to straight C chains that experience more LDF than branched C shapes)
- all molecules can experience LDF

Question 8

dipole-dipole

Answer 8

exists between 2 polar molecules: when 1 molecule’s partially positive side is attracted to another molecule’s partially negative side

Question 9

hydrogen bonding

Answer 9

when an e-deficient H makes a partial bond with a lone pair on a different molecule –> like a special case of dipole-dipole
- the H must be directly bonded to a F, O, or N (the most e-neg and smallest elements)
- there must be a lone pair in addition to either an F, O, or N
- a bond must be all the e- the H has, so the H must be extremely partially positive

Question 10

alcohols

Answer 10

all alcohols can h-bond because they all have a C bonded to an O (with 2 lone pairs) bonded to an H

Question 11

solution

Answer 11

a homogenous mixture with 2+ substances

Question 12

solute

Answer 12

what’s being dissolved

Question 13

solvent

Answer 13

what’s doing the dissolving

Question 14

solubility

Answer 14

a solute’s max. concentration that can be dissolved in a given solute in certain conditions

Question 15

solvation/dissolution

Answer 15

the process by which solutes dissolve into the solvent

Question 16

miscible

Answer 16

when 2 liquids can turn into a homogeneous mixture

Question 17

immiscible

Answer 17

when 2 liquids can’t turn into a homogeneous mixture

Question 18

dilute solutions

Answer 18

relatively low solute per unit of solvent

Question 19

concentrated solutions

Answer 19

relatively high solute per unit of solvent

Question 20

saturated solutions

Answer 20

maximum amount of solute dissolved

Question 21

unsaturated solutions

Answer 21

less than the maximum amount of solute dissolved

Question 22

supersaturated solutions

Answer 22

more than the maximum amount of solute dissolved (prone to crystal formation)

Question 23

describe the solvation process

Answer 23

1. solute particles separate from each other (IMF broken, requires energy)
2. solvent particles separate from each other (IMF broken, requires energy)
3. solvent and solute mix and interact (new IMF between the solute and solvent molecules; releases E)

Question 24

h-bond acceptor

Answer 24

molecules that can’t h-bond but have a lone pair on F, O, or N, which can accept e-deficient H to form an h-bond
- H-bond acceptors can mix with h-bonding solvents TO A POINT
- solubility is lower the more nonpolars (C) in an acceptor

Question 25

ionic compound solubility

Answer 25

aka ion-dipole force
polar molecules can surround ions, stabilizing ionic charge and allowing for solvation: only H2O is small and polar enough to do this as a solvent, and most ionic compounds dissolve in it

Question 26

biphasic liquid mixture

Answer 26

immiscible liquids form distinct layers, with the denser liquid on the bottom

Question 27

hydrophilic
hydrophobic
amphiphilic

Answer 27

doesn’t mix with water
mixes with water
a molecule with hydrophobic and hydrophilic regions

Question 28

1 mole

Answer 28

6.023 x 10^23
aka Avagadro’s Number

Question 29

concentration

Answer 29

the measure of the amount of solute in a solution

Question 30

percent by mass

Answer 30

better for liquids

%mass = [(mass solute)/(mass solution)] x 100

Question 31

percent by volume

Answer 31

better for solids

%vol. = [(volume solute/(volume solution)] x 100

Question 32

mole fraction

Answer 32

X = n (subscript) solute / n (subscript) total)

Usually ends up needing mole mass to set up with volume → like “volume x 1 mole/mm”, then plugging in for the solute; doesn’t end with a unit

Question 33

molarity

Answer 33

aka M
M = n/v (moles over L)

The moles solute per liter (L) of solution; most common and important for chemists

Question 34

dilution

Answer 34

a solution with a fixed amount of solute can’t be concentrated in a controlled manner, but can be diluted to have a solution with a desired lesser Molarity