Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
|
saturated solution
|
one that is, or could be, in equilibrium with undissolved solute
|
|
|
unsaturated solution
|
contains a lower conentration of solute than the saturated solution
|
|
|
supersautrated solution
|
contains a higher concentration of dissolved solute than a saturated solution of that temperature
|
|
|
what happens when a solution is supersaturated
|
excess solute stats in solution, if a small crystal is put in, excess solute comes out of solution
|
|
|
2 categories of solutes in H2O
|
nonelectrolytes and electrolytes
|
|
|
nonelectrolytes
|
doesn't conduct electricity
molecular substances that dissolve as molecules molecules are nuetral and can't carry a currant |
|
|
example of nonlectrolyte
|
CH3OH
|
|
|
electrolytes
|
solutes whos water solutions conduct an electric current
-produce ions in solution -charges ions migrate in an electric field carrying a current -ionized in H2O |
|
|
what make for strong electrolytes
|
strong acids and bases
|
|
|
example of electrolyte
|
NaCl--> Na+ and Cl-
|
|
|
what are weak acids and bases in H2O
|
a mixture of molecules and ions
|
|
|
mass % formula
|
mass solute
----------- total mass solute+solvent times 100% |
|
|
mole fraction formula
|
#moles A
--------- total# moles in mixture |
|
|
molality formula
|
#moles of solute
---------------- 1 kg of solvent or n -- kg |
|
|
molarity formula
|
#moles of solute
---------------- #liters of solution orrr n -- L |
|
|
what does 1 kg of H2O equal in liters
|
1 L H2O
|
|
|
when given mass percent, what do u start with
|
100 g solvent
|
|
|
when given molality, what do u start with
|
1000 g solvent
|
|
|
when given mole fraction, what do u start with
|
1 mol (solute+solvent)
|
|
|
when given molarity, what do u start with
|
1 L solution
|
|
|
what is the cardinal rule of solubility
|
Like dissolves Like
-polar dissolves polar (or ionic solutes) -nonpolar dissolves nonpolar |
|
|
what are the 3 steps in the formation of a solution and what kind of energy change are they
|
1. deltaH1- breaking up the solute into individual pieces (endo)
2. deltaH2-overcoming IMF in solvent to make room for solute (endo) 3. deltaH3- allowing solute and solvent to interact and form a solution (exo UNLESS there is no attraction) |
|
|
enthalpy of solution
|
deltaH1+deltaH2+deltaH3
|
|
|
how do you decide if the solution will be endo(+) or exo(-)
|
depending if the deltaH3's exothermic energy is greater than the sum of deltaH1 and deltaH2
|
|
|
why doesnt oil mix with water?
|
1. low, + deltaH1 for a nonpolar solute-only condon forces have to be overcome, but learge for large nonmolar molecules
2. deltaH2 is + and large- hard to break apart H2O molecules because of its bonding 3. deltaH3 is small since there are very little interactions between polar and nonpolar molecules soo the result solution will be large and positive because a large amount of energy would have to be spent to make the solution so it doesn't really occur |
|
|
why does an ionic solute like NaCl dissolve in H20
|
1. deltaH1 is large and positive to break electrostatic attraction in ionic crystal
2. deltaH2 is large and positive to overcome H-bonds in H2O 3. deltaH3 is large and negative because of molecule-ion attractions soo deltaH3 compensates for deltaH1 and 2 -dissolving increases entropy (disordre) |
|
|
entropy
|
disorder
|
|
|
why do alcohols dissolve in H2O
|
because heydrogen bonds form between H2O and the -OH groups
|
|
|
how does temp affect solubility
|
-an increase in temp always shifts the equilibrium in favor of an endothermic process
-if the solution is +, increasing temp increases solubility -if the solution is -, increasing temp decreases the soluility |
|
|
what is different about temp and solubility of a gas
|
when a gas is dissolved in a liquid, gas coming out of a solutioon is endothermic, so incrasing the temp DECREASES the solubility of a gas
-all gases in H2O are less soluble with increasing temp |
