Chpt 13: Properties of Solutions

Question 1

Ione pair???

Answer 1

What you call previously dissociated ions (like Na+ and Cl-) that have re-combined temporarily (bc of electrostatic attraction) in a sln, causing a slight shift the van’t Hoff “i” value

More common in diluted slns

Question 2

what does the term Solubility describe?

Answer 2

amt of solute needed to form a saturated sln at a given temp, assuming that excess solute is present

amt that something dissolves in a given quantity of solvent

Question 3

What does the term ‘solute’ describe in a solution?

Answer 3

the part/component of the solution in the smaller amount

exp. in salt water solution, salt is the solute

Question 4

in the enthalpy of solution equation, is delta enthalpy of solvent endothermic or exothermic?

Answer 4

endothermic.

breaking bonds requires energy

Question 5

what does Henry’s Law describe/quantify?

Answer 5

the impact of vapor pressure on the solubility of gases

Question 6

What condition(s)/temperature does Boiling point describe?

Answer 6

the temp at which a liquid achieves vapor pressure of 1 atm

Question 7

as solution-ness of a system goes up, entropy goes…

Answer 7

up

Question 8

what is the van’t Hoff factor?

Answer 8

The number of fragments that a solute break up into for a particular solvent

represented by “i”

Question 9

What does it mean to say that the formation of a solution is ‘spontaneous’?

Answer 9

that no energy had to be added to the system in order to facilitate the solution forming

Question 10

is dissolution the same as dissociation?

Answer 10

no

Question 11

what is a hydrate?

Answer 11

a compound, typically a crystalline one, in which water molecules are chemically bound to another compound or an element (even after the aq water is evaporated off)

Question 12

Barring physical barriers between particles, do gas particles always spread out and form homogenous mixtures/solutions?

Answer 12

yes

Question 13

what is the order of the intermolecular forces (listed from weakest to strongest)?

Answer 13

dispersion force
dipole dipole force
hydrogen bond
ion dipole force
ionic bond

Question 14

what does Volatile/volatility describe?

Answer 14

the tendency of a substance to vaporize (r/t vapor pressure).

Question 15

what does the term ‘dissociation’ describe?

Answer 15

when a solute is ionized in solution

Question 16

What does the term ‘hydration’ describe?

Answer 16

solvation process in which water is the solvent

Question 17

what is the formula for Henry’s Law?

Answer 17

Sg = kPg

solubility of gas = (k constant)(partial pressure of gas above sln)

Question 18

What does solution formation have to do with entropy (disorder) and enthalpy (energy) in a system?

Answer 18

systems tend to try to decrease their entropy and increase their enthalpy; solution formation helps systems to achieve both

Question 19

what is the Tyndell effect?

Answer 19

property/ability of colloids to scatter visible light

Question 20

in the enthalpy of solution equation, is delta enthalpy of solute endothermic or exothermic?

Answer 20

endothermic.

breaking bonds requires energy

Question 21

What 2 factors can inhibit a components in a system from forming a solution SPONTANEOUSLY?

Answer 21

1. physical barriers

2. miss-matched intermolecular forces

Question 22

what does it mean to call solution components ‘Immiscible’?

Answer 22

that the components will NOT mix together in all proportions

specifically applies to liquids (that don’t dissolve well in one another)

Question 23

what is an Unsaturated solution?

Answer 23

a sln that has LESS solute than what is needed to achieve equilibrium

no undissolved solute left

Question 24

what does it mean to call solution components ‘Miscible’?

Answer 24

that the components will mix together in all proportions

specifically applies to liquids (that dissolve well in one another)

Question 25

what does the term ‘Supersaturated solution’ describe?

Answer 25

a sln that has more solute than what is needed to achieve equilibrium (because the sln was heated and then extra solute was added to it)

considered unstable

Question 26

Do intermolecular forces (between particles) impact the likelihood of gas solution formation?

Answer 26

no. gases always mix.

intermolecular forces really only impact solution formation when considering liquids and solids.

Question 27

Do exothermic processes tend to be spontaneous?

Answer 27

yes

Question 28

What 2 conditions enable a solution process to be described as ‘spontaneous’?

Answer 28

1. solution formation increases the systems’s entropy (disorder)
2. solution formation decreases the system’s enthalpy (energy)

Question 29

what is the term ‘crystallization’ meant to describe?

Answer 29

the opposite of solution formation;

when dissolved particles from a solid solute come back together to rejoin/reform the solid

Question 30

what makes a solution ‘ideal’

Answer 30

when the solutes don’t experience any ion pairing

Question 31

What does the term ‘solution process’ describe?

Answer 31

what happens when one substance disperses uniformly throughout another

Question 32

in the enthalpy of solution equation, is delta enthalpy of mixture endothermic or exothermic?

Answer 32

exothermic.

making bonds releases energy

Question 33

What does the term ‘solvent’ describe in a solution?

Answer 33

the part/component of the solution in largest amount

exp. in salt water solution, water is the solvent

Question 34

what does the term ‘Saturated solution’ describe?

Answer 34

a solution in dynamic equilibrium

Question 35

what is vapor pressure?

Answer 35

the pressure caused by liquid molecules that have taken on enough energy to escape into the gas phase and exert pressure onto the liquid

Question 36

What 2 factors impact the likelihood that a solution will form?

Answer 36

1. tendency towards mixing (tendency of components to mix/spread in the absence of barriers)
2. intermolecular forces

Question 37

what does the term ‘solvation’ describe?

Answer 37

interactions whereby ions are surrounded by solvent molecules due to attractive forces

Question 38

what is a solution?

Answer 38

what you get when one substance disperses uniformly in another

Question 39

what is a Colloid?

Answer 39

a type of mixture (somewhere between a homogenous mixture and a heterogenous mixture) whose solutes are big enough to scatter light but small enough to not experience gravity

Question 40

how is moLALity described?

Answer 40

moles (of solute) per kg (of solvent)

Question 41

what is osmotic pressure?

Answer 41

the pressure that must be applied to resist the pressure of a pure solvent moving across a membrane into a solution

Question 42

How do you calculate the vapor pressure for a solution made of TWO volatile substances? (exp. water and ethanol)

Answer 42

you have to do:

mole fraction solvent * vapor pressure of pure solvent) + (mole fraction solute * vapor pressure pure solute

Question 43

what does the term ‘Dynamic Equilibrium’ describe?

Answer 43

when the rate of dissolution and crystallization in a solution are equal, and the amount of solute stays the same

Question 44

as solution-ness of a system goes up, enthalpy goes

Answer 44

down