Solution (9)

Question 1

Solution

Answer 1

homogeneous mixtures composed of two or more substance

Question 2

Solvent

Answer 2

component of solution that remain same phase after mixing

ex: water

Question 3

Solute

Answer 3

dissolved in solvent ( NaCl, CO2 , NH3…)

Question 4

Solvation

Answer 4

electrostatic interaction between solute and solvent molecules.

Water solvent is called hydration

solvation breaks down IMF between solutes and solvent molecules together

Question 5

The solubility of gas and liquid

Answer 5

Lowering the temperature of a liquid favors the solubility of gas and liquid.

Question 6

Dissolution

Answer 6

Dissolution will happen spontaneously depends on both the change in enthalpy and the change in entropy for the solute and solvent of the system.

Question 7

Solubility

Answer 7

the maximum amount of substance that can be dissolved in a particular solvent at a given temperature.
expressed as molar solubility

Molar solubility: molarity of solute at saturation

Question 8

Aqueous solution

Answer 8

the solution is where the solvent is water

Question 9

Percent composition by mass

Answer 9

(mass of solute/ total mass of the solution ) x 100

Question 10

Mole fraction (X)

Answer 10

Xa = moles of a / total moles of all species

the sum of mole fraction in the system will always equal 1

Question 11

Molarity

Answer 11

M = moles of solute / liters of solution

Question 12

molality

Answer 12

m = moles of solute/kilograms of solvent

Question 13

Dilution equation

Answer 13

m1 v1 = m2 v2

Question 14

Ksp vs IP

Answer 14

Ksp at equilibrium
IP not at equilibrium

IP < Ksp: unsaturated solution, continue dissolve
IP > Ksp: supersaturated, precipitate
IP = Ksp: saturated, at equilibrium

Question 15

Kf

Answer 15

complex formation. Its value is generally much greater than Ksp

The formation of complex increases the solubility of other salts containing the same ions b/c it uses up the products of that dissolution reaction, shifting the equilibrium to the right.

Question 16

Common ion effect

Answer 16

decreases the solubility of a compound in a solution that already contains one of the ions in the compound. The presence of that ion in solution shifts the dissolution reaction to the left, decreasing its dissociation.

Question 17

Vapor pressure depression (Raoult’s law)

Answer 17

the presence of other solutes decreases the evaporation rate of a solvent without affecting its condensation rate, decreasing vapor pressure.

As vapor pressure decreases, the temperature (energy) required to boil the liquid must be raised.

Pa = Xa P°a
Pa = vapor pressure
P°a = initial vapor pressure without solute

Question 18

Boiling point elevation

Answer 18

ΔTb = iKbm

i = van't Hoff factor (ions)
Kb = proportionality constant 
m = molality 

example: NaCl contains 2 i b/c two ions

Question 19

Freezing point depression

Answer 19

ΔTf = iKfm

i = van't Hoff factor (ions)
Kb = proportionality constant 
m = molaltiy

Question 20

Osmotic Pressure

Answer 20

π = iMRT

i = van't Hoff factor (ions)
M = molarity
R = ideal gas constant
T = temperature