o chem lab final

nonpolar

C with low electroneg

polar

C with electroneg (top right), double bonds with O

very polar

hydrogen bonds

hexane

nonpolar

ethyl acetata

polar

more polar

low on plate low Rf

less polar

high on plate high rf

mobile phase

opposite polar rules

bottom of plate

stationary

moving up

mobile

liquid liquid extraction

compound is distributed between 2 immisicible solvents

reactant sodium benzoate

soluble in an aqueous environment

product benzoic acid

not soluble in an aqueous environment

changing solubility to better seperate a mixture in extraction

acid-base chemistry

recrystalization solvent rules

doesnt react with compound, dissolves compound when hot, doesnt dissolve when cold, dissolves impurity at all or none temps

insoluble impurities

doesnt dissolve at high temps and must be filtered out

solubility of benzoic acid

drops at low temps, causing the compound to crystallize out of the solution

recrystillization product is dried by

continuing to pull air through after liquid is gone

recrystalization wash rules

compound is insoluble in it, impurities are soluble in it

impure

broad and lower than expected melting point

pure

narrow and expected melting point

column chromatography purpose

seperate fluroene and fluroenone

column chromatography staionary phase

exits pipette first, bottom of pipette

column chromotography mobile phase

top of pipette

elutes from pipette first

least polar

what spots appear on quickm and dirty tlc

the tubes that contained the compound that exited the pipette

fluorenone

more polar

fluorene

less polar

more hexanes

elution of polar compounds

more ethyl acetate

compounds move faster and increased elution strength

higher rf

elutes earlier

lower rf

needs stronger solvent to leave column

slimination microwave heating

speeds up acid-catalyde dehydrations

effective distillation

materials have different boiling points

lowest boiling point

distilled and collected first

bromine test positive

yellow, color dissapears, alkene or alkyne

bromine test negative

orange, color persists

bromine test flase negative

alkene is unreactive

bromine test false positive

phenol or ketone

permangenate test positive

brown, color disappears, alkene or alkyne

permangenate test negative

purple, color persisits, double bond

permangenate test false positive

aldehydes, alchohols

alkene addition

formation of bis-bromohydrin

epoxide formation

making bis-epoxide from bis-bromohydrin

epoxide formation analysis

match mass spectra to compounds by looking at raw mass value and presence of peak ratios that indicate specific elements and multi addition products

distillation and GC process

vaporize liquid, condense vapor, collect condensation

theoretical plate

vaporization condensation event

vertical

condensation

horizontal

vaporization

triangle

theoretical plate

steel wool

increases surface area for vapor-liquid contact

gas chromotography

sperates and analyzes compoubnds that can be vaporized without decomposition

GC mobile phase

inert carrier gas

GC stationary phase

steel wool

simple distillation

large boiling point difference, few theoretical plates

fractional distillation

steel wool, more plates, better seperation, more anisole

GC seperates based on

boiling point and polarity

low boiling point

short retertion time

high boiling point

long retention time

peak area percentage

polarity and composition of fractions

nucleophillic substituition product

50/50 distribution of Cl/Br products

reaction

induce chemical transformation

work up

quench excess reactants or reagents, sperate desired compounds

purify

isolate desired compounds, chromotography and crystillization

analyze

characterize desired compounds, spectrometric