CHE 002B: Ch. 17 Properties of Solutions

Solution

homogeneous mixture composed of a solute and solvent, typically water

Mole Fraction (X_ⁱ)

moles of component/ total moles of all components

Molarity (M)

moles solute / volume of solution

Molality (m)

moles of solute / kg of solvent

Molality is independent of ___ and analyzes the solvent

temperature

When a solution is mixed, ____ increases

entropy

In order for it to be a spontaneous process, it cannot be a ______ process

endothermic

Polar dissolves in ______

polar solvents

Nonpolar dissolves in ______

nonpolar solvents

What effects the solubility of gas?

1. temperature - decreases as it increases

2. pressure

Henry’s Law

solubility increases as pressure increases

• C = KPgas

Colligative Properties

1. Boiling Point Elevation

2. Freezing Point Depression

3. Vapor Pressure Lowering

4. Osmotic Pressure

van’t Hoff Factor (i)

the concentration of solute particle is:

1. equal to 1 for nonelectrolytes

2. different for electrolytes

Strong Electrolytes

equal to the number of ions formed when dissolves

Weak Electrolytes

must consider the degree of ionization

1 < i < 2

Boiling Point Elevation

bp will be higher at a given pressure when a nonvolatile solute is present

Raoult’s Law

vapor pressure is lowered when a nonvolatile solute is present resulting in the elevation of bp

BP elevation is proportional to ______

molality

Freezing Point Depression

adding solute decreases the concentration of solvent thus decreasing the rate of crystallization and fp

Osmosis

the net flow of solvent from a pure solvent to the solution from high C to low C

Osmotic Pressure (pi)

the pressure required to stop osmosis

Osmotic Pressure for Dilute Solution

pi(V) = inRT ==> pi = iMRT