Chapter 9- Solutions

Question 1

When new interactions are stronger than the original ones in the solution

Answer 1

Exothermic and its favored at low temperatures

Question 2

When the new interactions are weaker than the original ones in a solution

Answer 2

Endothermic. Favored at high temperatures

Question 3

Ideal solutions

Answer 3

Strength of original and new solution is same. Change in enthalpy is close to zero (dissolution = 0)

Question 4

What does 🔺G say about solubility?

Answer 4

+ means nonspontaneous and insoluble

• means spontaneous and soluble

Question 5

Molar solubility middle mark

Answer 5

0.1M and above - soluble

Under 0.1M- sparingly soluble

Question 6

2 must know solubility rules

Answer 6

1. All salts containing ammonium (NH4+) and alkali metals (group 1) cations are water soluble.
2. All salts containing nitrate (NO3-) and acetate (CH3COO-) anions are water soluble.

Question 7

Chemically reacting species in a molecule?

Answer 7

Cation

Question 8

Molarity

Answer 8

moles of solute / liters of solution

Question 9

Molality

Answer 9

moles of solute / kilograms of solvent

Question 10

Normality

Answer 10

Reaction dependent. If in a solution something will accept 5 electrons then it’s 5N.

Question 11

Dilution equation

Answer 11

MiVi = MfVf

M- Molarity
V- volume

Question 12

When is the change in free energy zero?

Answer 12

Equilibrium

Question 13

Ksp

Answer 13

Solubility product constant/ equilibrium constant. No liquids or solids included.

Question 14

Ion product

Answer 14

Used to determine whether the solution has reached saturation (same equation as Ksp)

Question 15

Relationship b/w IP and Ksp

Answer 15

IP > Ksp -supersaturated/precipitation will occur

Question 16

Molar solubility

Answer 16

Maximum number of moles that can be solvated before the solution becomes saturated

Question 17

Sparingly soluble salt of general formula MX or MX2 or MX3 will have what Ksp (respectively). Assuming no common ion effect. X = molar solubility.

Answer 17

MX: Ksp = x^2

MX2: Ksp = 4x^3

MX3: Ksp = 27x^4

Question 18

Common ion effect

Answer 18

Reduction in molar solubility when the solvent already has one of the solutes constituent ions.

Question 19

Colligative properties

Answer 19

Physical properties of solutions that are dependent on concentration of dissolved particles but not the chemical identity. (Ex: vapor pressure depression, boiling point elevation, etc.)

Question 20

Raoults law for vapor pressure depression.

Answer 20

As solute is added to solvent the vapor pressure of solvent decreases. Mainly if the two are similar reactants.
Pa = XaPa*

Pa-vapor pressure of solvent A
Xa-mole fraction of solvent A in solution
Pa*-vapor pressure of solvent A in pure state

Question 21

Boiling point

Answer 21

Temperature where the vapor pressure of the liquid equals the ambient (incident) pressure

Question 22

What happens to the boiling point of a solution when you add a solute?

Answer 22

Boiling point increases

Question 23

Boiling point elevation formula

Answer 23

Increase in bp = iKbm

i- vant hold factor(number of particles the compound dissociates into)
Kb- proportionality constant (given)
m- Molality of solution

Question 24

Freezing point depression equation

Answer 24

🔺Tf = iKfm

i- vant Hoff factor
Kf- proportionality constant (given)
m- Molality

Question 25

Do pure solutions or mixed have lower freezing point?

Answer 25

Mixed solutions have lower freezing points. Harder to get lattice structure with mixtures

Question 26

Boiling point of water

Answer 26

373K

Question 27

Freezing point of water

Answer 27

273K

Question 28

Relationship between solubility of gases in liquids and atmospheric pressure

Answer 28

Directly proportional