CH 220C Quiz 2

four criteria for Sx

1. immiscible with S0
2. cannot react irreversibly with compound
3. Sx should be as specific to compound as possible
4. Sx must be easily removable after extraction

recrystallization and temperature

solubility of impurity is room temp, solubility of pure sub. is higher; high heat rxn forms pure solid precipitate and impurity remains in liq. soln

seperatory funnel

vented to relieve pressure that builds with shaking

basic solution without precipitate

small layer of ethyl acetate needs to be blown off

cis configuration

electrons in the same plain repel each other and create strain

bromine spill

sodium thiosulfate cleanup

MP range

lower temp is first drop that appears; higher temp is when all solid is melted

shaking separatory funnel purpose

increases surface area between immiscible liquids so the eq. distribution of solute between both layers is achieved quickly

emulsion

colloidal mixture of the two solvents, not producing layers from overshaking

partitioning

difference of solubilities in two immiscible solvents (selective dissolution)

K and partitioning

K>1 goes to Sx, K<1 goes to S0

basic aq extraction solution

strong enough base will convert HA to A- making it polar (K>1) and soluble in aq. phase; neutralization with acid reforms HA as solid or second liq. layer

N recovery

achieved by removing organic solvent S0

choose base depending on…

acidity of HA defined by
Ka(HA) = ([A-][H+])/[HA]
pKa = -logKa

base effectiveness given by…

acidities of HA and HB defined by
Keq = ([A-][HB])/([HA][B-])
Ka(HB) = ([B-][H+])/[HB]
Keq = Ka(HA)/Ka (HB)
log Keq = log Ka(HA) - log Ka(HB)
any base with HB pKa > than that of HA will be effective (Keq>1)

common physical constants

MP, BP, index of refraction (n), density (d), specific rotation (alpha), solubility

melting point

temp at which liq. and solid phase exist at eq. w/o change in temp

impurities and MP

impurities depress MP

eutectic point

eq. composition at which pure A and B melt in constant ratio

MP range depends on

1. sample quantity
2. state of subdivision
3. rate of heating
4. purity/chemical charac. of sample

conformational isomer

interconverted about single bond rotation

configurational isomer

interconverted via bond breakage/remaking

ethyl acetate MSDS

- not C
- possible M
- severe FH
- irritant

NaOH MSDS

- not C
- not M
- not FH
- irritant

HCl MSDS

- not C
- possible M
- not FH
- irritant

sodium sulfate

- known C
- known M
- not FH
- irritant

3-Nitroaniline MSDS

- not C
- not M
- toxic fumes in fire
- irritant

4-Nitroaniline MSDS

- not C
- not M
- toxic fumes in fire
- irritant

2-Methyl-4-Nitroaniline MSDS

- not C
- not M
- toxic fumes in fire
- irritant

9-Fluorenone MSDS

- possible C
- not M
- moderate FH
- irritant

Fluorene MSDS

- not C
- not M
- slight FH
- irritant

anthracene MSDS

- known C
- not M
- moderate FH
- irritant

phenanthrene MSDS

- not C
- not M
- moderate FH
- irritant

methanol msds

- not C
- possible M
- severe FH
- irritant

R-carvone MSDS

- not C
- not M
- moderate FH
- irritant

S-carvone MSDS

- not C
- not M
- moderate FH
- irritant

Bromine MSDS

- not C
- not M
- not FH
- irritant

cyclohexene MSDS

- not C
- not M
- severe FH
- irritant

dichloromethane MSDS

- known C
- possible M
- slight FH
- irritant

dimethyl fumarate MSDS

- not C
- not M
- slight FH
- irritant

ethanol MSDS

- not C
- possible M
- severe FH
- irritant

dimethyl maleate

- not C
- not M
- moderate FH
- irritant