Homogeneous Mixture

mixtures who's components are uniformly intermingled on a molecular level. 

Component

each of the substances in a solution.

Solvent  

the component present in the greatest amount. 

ΔH₁: Separation of solute molecules

ΔH₂: Separation of solvent molecules

ΔH₃ Formation of solute-solvent molecules

ΔH₁ & ΔH₂ represent endothermic processes; ΔH₃ represents an exothermic process.

The state of the solvent determines...

The state of the solution.

Spontaneous Reactions

Processes in which the energy content of the system decreases and which the disorder (entropy) of the system increases. 

Solubility 

The amount of solute needed to form a saturated solution in a given quantity of solvent. 

the extremes
 

unsaturated-too little

supersaturated-too much 

Like dissolves like 

Substances with similar intermolecular attractive forces tend to be soluable in one another.

i.e. non-polar to non-polar more soluable thatn non-polar to polar. 

Solubiliy of a gas 

Increases in direct proportion to its partial pressure above the solution. 

Henry's Law 

S_g = kP_g 

where S_g is the solubility of the gas in the solution phase, P_g is the partial pressure of the gas over the solution, and k is the proportionality constant, or Henry's law constant in units mol/L-atm 

Temperature effects on solutions 

The solubility of most solid solutes in water increases as the temperature of the solution increases.

The solubility of gases in water decreases with increasing temperature. i.e less oxygen in hot water than in cold water. 

Mass % of component    

mass of component in soln.    _{X 100}

ppm of component 

mass of component in soln. _X 10⁶
total mass of soln

Mole fraction of component (X_component)

moles of component
total moles of all components

Molarity (M)

moles of solute
liters soln.

depends on volume of solution and therefore temperature

Molality (m) 

moles solute
kilograms of solvent

depends on mass of solvent and is independent of temperature. 

Colligative Properties 

physical properties of a solution that depends on the concentration, but not the kind or identity of the solute. 

Raoult's Law 

P_A = X_AP^°_A 

Xa is the mole fraction of the solvent in the soln.

P^°_A is the vapor pressure of the pure solvent. 

When we increase the mole fraction of the solute, the vapor pressure of the pure solution will be reduced. 

Boiling Point Elevation 

ΔT_b = K_b · m

Kb is the molal boiling-point-elevation constant

m is the molality

Freezing Point Depression 

ΔT_f = K_f · m

K_f is the molal freesing-point-depression constant

m is the molality

Osmotic Pressure 

∏= MRT