Chapter 14: Solutions, Osmosis & All The Things That Make Me Happy

Osmotic Pressure

Pressure required to stop osmotic flow

Solute molecules interfere with solver molecules from crossing the memebrane so

they disallow the solvent to crossover, like blocking a pipe with your hand

Once we reach osmotic pressure

the rate of transfer of solvent decreases because we’ve reached maximum pressure.

Osmotic pressure for non ionic solvents equals

molarity times r constant times temperature (K, K,K)

Reverse Osmosis

Reverse osmosis that hopes because external pressure exceeded the osmotic pressure. So instead of the solvent flowing to the thing with lower concentration, it flows to the thing with higher concentration.

The purpose of osmosis

to balance the concentration of solute in two solutions

When we add a nonvolatile solvent to a solute boiling point…

increases.

when we add a nonvolatile to a solute

freezing point decreases

If boiling point increases

freezing point decreases

change in boiling point elevation =

molal boiling point time molality times i(van Hoff factor)

Change in freezing point after adding a solvent is

-molal freezing point times molality time i(van Hoff factor)

Raoults Law

Pressure of the solution = mole fraction of solvent times standard pressure of the solvent

osmotic pressure when we have an ionic solvent

polarity times I(van Hoff factor) times R constant times T in Kelvin.

The iActually phenomenon

The higher concentration of an ionic solvent we have, the more the Vann Hoff factor will be lower than expected, bevcsue they are like my parents in 2012.

Enthalpy of a solution is

the sum of each enthalpies at each step

Explain each step that goes into creating a solution

Yes Yes Yes

In a a solution we have three interactions…

solute-solute, solvent-solvent, and solvent-solute

In a solution what molecules must split away and what molecules must come together?

solvent-solvent molecules must split, solute-solute molecules must split away and solute-solvent solutions must come together

What kind of reaction is solute-solute breaking and solvent-solvent breaking

endothermic

What kind of reaction is solvent-solute coming together

exothermic

Do intermolecular forces play a role in how solutes and solvents interact?

Of course they do!

If the intermolecular forces between like and unlike molecules are of equal strength then..

we get a completely homogeneous solution

If The forces between solvent and solute are stronger than the forces between like molecules,

then a solution will form becase they want each other so badly.

If the forces between solute and solvent are weaker than the other two,

then complete mixing MIGHT occur but it will be endothermic

If solute solute and solvent solvent interactions are much stronger, then..

we get a heterogeneous mixture (they don’t mix)

Like dissolves

Like

When a solvent is ionic,

then it will dissascoate in solution

Hydrates ions in solutions means

ions that are encases either positively or negatively by H2o atoms. (think NaCl)

Solubility

How much solute dissolves in a given amount of solvent at a specific temperature (write a table like in the video)

Saturates Solution

amount of solvent equals the the maximum solubility at a given temp (table and drawing please)

Unsaturated solution

amount of solute is significantly lower than the solubility at a given temp (table and explanation please)

Supersaturated Ablution

Amount of solute exceeds the solubility at a given temp

A saturated solution is a

HOMO

A unsaturated solution is a

SUPER HOMO

A supersaturated solution

Hetero

Solubility depends on

temperature, higher temp = higher solubility, lower temp = lower solubility

Explain how Chris did the experiment in lecture

ok ok ok ok

Adding s solvent makes freezing point

decrease and boiling point increase

Excess solute in a solvent will

crystallize !

For gases, solubility blank with an increase in temp (explain the fishes)

decreases

Explain fractional distillation

ok ok

Azetrope

solution where the boiling points create a local maximum or minimum

Dipole induced vs dipole native interactions in solutions, which is stronger, and it explains like dissolves like

ok

Why do solutions form?

to get to lower energies

delta g of a solution is

spontaneous if the solution forms