Chem properties of solutions chp. 11

Osmosis

spontaneous movement of water through a semipermeable membrane from high conc to low conc (moves towards high conc of solute) in order to equalize solute conc.

Types of solutions

• Hypertonic: solution contains higher conc of solute than subject. (more solute surrounds cell)

• Hypotonic: solution contains lower conc of solute than subject. (more solute within cell than around it)

• Isotonic: even amount of solute within solution and subject

osmotic pressure

Pressure applied to semipermeable membrane to stop natural flow of water from low solute conc to high solute conc.

colligative property (pressure depends on amount of solute dissolved in solvent)

n = MRT

Vant hoff factor (i)

ratio of solute particles dissociated in solvent to particles had solute not dissociated (basically just how many ions does compound form)

ex.NaCl dissociates into Na+ and Cl- so its i=2

nonelectrolytes have i=1

Reverse osmosis

one of two processes of making a hypertonic solution (water) drinkable by removing ions from sea water. Distillation is the second process

Vapor Pressure

Pressure exerted by a gas in equilibrium with its liquid phase at a given temperature (tendency for material to change into gas or vapor phase)

Factors effecting vapor pressure

• Higher temperature increases vapor pressure (more particles have enough energy to jump into gas phase)

• Stronger intermolecular forces decrease vapor pressure (takes more energy to break bonds)

• vapor pressure equaling atmospheric pressure means the liquid boils

• Adding solute lowers vapor pressure

Raoults Law

total vapor pressure in solution depends on vapor pressure and mole fraction of each component

P = x1P1 + x2P2

Fractional distillation

technique used to separate mixtures of compounds based on differences in boiling points

Molality

Only used when calculating boiling point elevation or freezing point depression. Ratio of mol of solute to Kg of solvent

Boiling point elevation and freezing point depression are colligative?

They are colligative properties that rely on solute particle conc.