HYS - CH:9 - Solubility

Question 1

solute

Answer 1

thing being dissolved

Question 2

solvent

Answer 2

material doing the dissolving

Question 3

units of solubility

Answer 3

mass per unit volume of solvent
-molarity and molality

molar solubility
- moles/Liter

solubilty product Ksp

Question 4

molality

Answer 4

describes number of moles of solute being dissolved and what mass of solvent the solute is dissolved in

units moles of solute/kilograms of solvent

Question 5

Molarity, M and preperation

Answer 5

how many moles of a solute are dissolved in each liter of a solvent
given the moles of solute we can find the volume
units moles/L

to prepare we
1. add solute to solution with less than target volume to not create too much of solution
2. once dissolved we add solvent until desired molarity is reached
3. measuring of volume must be done after dissolving since volume of seperate components wont add
4. divide volume by moles/volume to get molarity

Question 6

why are molality and molarity nearly equivelant

Answer 6

1 L water ~ 1 kg water

for non aqeous solvents they can differ a lot

Question 7

molAR and litER means

Answer 7

molarity uses liters of solvent

Question 8

molAL and kilogrAM means

Answer 8

molality is for kg of solvent

Question 9

saturated solution

Answer 9

as much solute dissolved as can be dissolved in that solution

Question 10

molar solubility

Answer 10

The molar solubility is the maximum moles of dissolved solute per one liter of solvent. Notice that the unit for molar solubility is moles per liter. That’s molarity!

units moles/Liter
(same as molarity)

Question 11

solubility product

Answer 11

special case of equilibrium constant

Ksp = [only products]
bc solids and pure liquids dont appear in equilibrium constants we have no denominator

The solubility product is a kind of equilibrium constant and its value depends on temperature. it is the equilibrium constant for a solid substance dissolving in an aqueous solution. It represents the level at which a solute dissolves in solution
- for when solution is saturated
- Ksp usually increases with an increase in temperature due to increased solubility.

Question 12

equilibrium constant K

Answer 12

[products]/[reactants] with coeffficients of equation becoming exponents

Question 13

. T/f? are Ksp temp and substance dependent

Answer 13

T

Question 14

super saturated

Answer 14

A supersaturated solution is a solution that contains more than the maximum amount of solute that is capable of being dissolved at a given temperature

Question 15

ion product: unsaturated, saturated, supersaturated

Answer 15

K sp equation but with current conditions
compare Ksp to IP

Ksp is a general property of solute in solvent
IP is a specific description of a solution

IP<Ksp: unsaturated less than max solute
IP = Ksp: saturated limit of solute, equilibrium
IP>Ksp: supersaturared with too much solute

Question 16

if you dissolve something up to saturation in hot solvent and allow it to cool what happens to IP and KSP

Answer 16

Ip constant
KSP drops

useful for sugars

Question 17

for what solutions does precipitation occur

Answer 17

supersaturated solutions

Question 18

sodium barium sulfate is mixed with water to product Ba2+ and S042-. What is the Ksp?

Answer 18

Ksp = [Ba2+][SO4 2-]

take the product of concentration of ions

solid BaSO4 should not appear

Question 19

15 grams of urea is dissolved in 100g of water. what is the molality of solution? molecular mass of urea is 60 g/mol

Answer 19

molality is # moles per solvent in kg

to find the moles use the mass 15 g divided by the molecular mass 60 g/mol to get 15/60 moles

we know the mass of solvent of water in kg is 100 g x 1 kg/1000 g = 0.1 kg

now take 15/60

Question 20

when the concentration of table salt in water has been reached it means

Answer 20

the dissolved solute is in equilibrium with its undissolved state

when concentration == solubility the solution has reached saturation at its equilibrium

Question 21

is CH3 COOH a salt?

Answer 21

has no anion and cation

not a salt

Question 22

w

which alkaline earth metal has the first ionization energy

Answer 22

alkaline is group 2
ionization decreases top to bottom
top is Be with greater electron attraction becuase electrons are closer to nucleus in Be

Question 23

electric potential energy for a point charge
moving an electron

Answer 23

Question 24

when an electron is added to a neutral atom

Answer 24

energy is released, leading to a more stable state

bc neg electron is brought closer to positive nucleus which decreases energy

Question 25

which is a polyatomic cation
Calcium
sulfate
hydroxide
hydronium

Answer 25

cation means positive

Ca2+ is a nonatomic cation
SO4 2- is a polyatomic anion
OH- is a polyatomic anion
** HsO+ is a polyatomic cation **

Question 26

what kind of reaction is this

Answer 26

autoionization
water looses H and forms OH-
hydrogen protenates another water to form hydronium ion H30+

Question 27

bronsted lowry acid and base makes

Answer 27

a salt plus water

Question 28

which is a weak acid
HBr, HI, HF, HClO4

Answer 28

HF

Question 29

Answer 29

bc products are favored than reactants, the Keq >1

Question 30

when are reactants and products favored

when Keq = 1…
when keq >1…
when Keg <1…

Answer 30

when Keq = 1…reactants and products are favored
when keq >1…products favored
when Keg <1..reactants favored

Question 31

what happens to Kw and pH

Answer 31

at lower temps, less heat added
reverse reaction (backwards) is favored

less H+ and less OH-
decreases Kw

as concentration H decreases, pH increases

Question 32

if ph=3.7 what is pOH?

Answer 32

10-3.7
=10.3

Question 33

which is a triprotic acid?
sulfuric acid, carbonic acid, phosphoric acid, oxalic acid

Answer 33

phosphoric acid has 3 dissociable hydrogen atoms … triprotic acid