Chem quiz - April 9

What are the two kinds of mixtures?

herterogenous and homogenous

what are the two kinds of homogenous mixtures?

solutions and colloids

what is the difference between solutions and colloids?

solutions are transparent to light, colloids are not

solvent

major component of the mixture; almost always a liquid

solute

minor component of the mixture; could be a liquid, solid or gas

solubility depends on

the strength of the attractions between solute and solvent particles

the stronger the attraction between solute and solvent

the greater the solubility

number of carbon atoms in a chain

affects solubility in polar solvents; the more of them, the less soluble in water

number of OH groups affect

solubility in polar solvents; the more of them, the more soluble in water

the dissolution of a solute in a solvent is a

physical change ( can be exothermic or endothermic)

solubility

the maximum amount of a substance that will dissolve in a given amount of solvent at a specific temperature

saturated solutoin

a solution contains the maximum amount of a dissolved solute at equilibrium

generally as temeprature increases

solubility of solid solutes in liquid solvents increases

generall as temperture decreases

the slubility of gas solutes in liquid solvens increases

the solubility of a gas in a liquid is directly proportional to

the partial pressure of the gas over teh liquid

Henry’s law

C=K.Pgas

molarity tells us

how much of a compound in moles ( mol) are dissolved in a liter (L) of solvent,

Dilute solution

contains small amount of solute relative to the solvent

concentrated solution

contains a large amount of solute relative to the solvent

Molarity ( M) is what equation/

moles of solute/ volume of solute ( in L)

how to make a dilute solution

take a solution of a known molarity and dilute it with more solvent

In the concentrated and diluted forms of the solution

the moles of solute remains the same

strong electrolyte

completely dissociate into ions when dissolved in water ( conduct electricity)

Weak electrolyte

partially dissociate into ions in water ( conduct electricity poorly)

non electrolyte

do not dissociate into ions when dissolvd in water ( do not conduct electriciy)

colligative properties

solution properties that depend on the number of dissolved particles, not the type of particles

vapor pressure is lower

for a solution than for a pure solvent; fewer soluent molecueles are at the surface to eveaporate since solute particles take up space

boiling point is higher

for a solution than it is for a pure solvent; fewer moleucules espcae into the vapor so more heat is required

boiling point eleveation is calcualted with

change in boiling point= iKbm

freezing point is lower for a

solution than for a pure solvent; solute molecules disperesed between solvent throughout solutoin makes it harder to order

the freezing point is calculated using q

the change in freezing point = i Kf m

new freezing point of solution is

normal fp - change in fp

new boiling point of solution is

normal bp + new bp

osmosis

the movemement of solvent molecules from a region of lower solute concentration to a region of higher solute concetration through a semipermiable membrane

osmotic pressure

the minimum pressure needed to stop osmosis

Osmolarity

describes the concentration of particles in solution

Osmole

the number of moles of partciles that contribute to the osmotic pressure of a solutio