CHEMISTRY 104 Help Sheet 4 Chapter 24 Part III Prepared by Dr Tony Jacob http www chem wisc edu areas clc Resource page Nuggets Functional Groups Part II Reactions Part I O FUNCTIONAL GROUPS the last 6 containing or N containing functional groups C Not all functional groups may be covered by each instructor your instructor will clarify the ones you are responsible for Functional Group Aldehyde Suffix an al Formula Other Info O O R C H or RCHO carbonyls i e contains are polar C 2 4 1 Ketone e g 3 chloro 1 butanal O R H and R H polar O an one R C R 3 or R C O R Cl methyl O 4 5 3 6 e g 4 5 dimethyl 3 hexanone Carboxylic acid an oic acid R C O H or RCOOH R methyl O O O 1 2 C R OH C H O R can be a H acidic pH 7 H bonding polar O 1 HO Ester O an oate R C O R or R COO R O R named 1st yl then named 2nd anoate R C O R but anoate Amine amine R C N R ethyl O 1 2 2 e g ethylbutanoate 4 polar usually amides are not named in Chem 104 O R O 1 3 Amide 3 2 4 3 3 dimethyl 1 butanoic acid R can be a H R H polar often smell nice or R CO NH2 NRR R 1 primary 2 secondary 3 tertiary NR3 H2O NR3H OH basic pH 7 all but 4 have H bonding polar alphabetize groups amine 1 R must H ethyl e g ethylpropylamine 1 2 propyl N H 1 3 2 O Aldehyde contains a carbonyl C O with at least one H attached R C H or R CHO O Ketone a carbonyl C O with no H attached R C R or R CO R R and R H otherwise it s an aldehyde O Carboxylic acid a carbonyl C O with a OH attached R C O H solution pH 7 can dissociate a H O with the COO group C O R C or R COOH R can be a H creates an acidic O O OH R C O H can undergo H bonding has resonance C O O O Ester R COO R R C O R R H otherwise it s a carboxylic acid many esters smell pleasant O R Amide R C O NR R R C N R R R can be H H bonding Amine N with a C attached to it NRR R H bonding creates basic solution pH 7 primary 1 N has 1 C attached secondary 2 N has 2 C attached tertiary 3 N has 3 C attached COMMON NAMES each instructor will clarify which commons names if any you are expected to know H3C CH3CHCH3 isopropyl C CH3 CH3 tert butyl t butyl H2C CH2 HC ethylene ethane CH acetylene ethyne OH H2C CH propylene H CH3OH CH3CH2OH methyl alcohol methanol ethyl alcohol ethanol CH3 OH OH C C H H H ethylene glycol H OH OH OH C C C H H H isopropyl alcohol O O H H gycerol glycerin H H formaldehyde acetaldehyde O C O O H O H benzaldehyde acetone OH formic acid H C O formate ion O O CH3 OH O OH acetic acid H3C C O acetate ion benzoic acid OH styrene xylenes phenol toluene NH2 aniline REACTIONS The instructor may not cover all of the reactions below 1 COMBUSTION complete Clue O2 is reactant burn combustion CxHy or CxHyOz O2 CO2 H2O 1st balance C then H then O 2C8H18 g 25O2 g 16CO2 g 18H2O g Incomplete Combustion if covered CxHy or CxHyOz O2 CO H2O 2C2H6 g 5O2 g 4CO g 6H2O g 1st balance C then H then O 2 ALKENES ALKYNES ADDITION add H2 Cl2 Br2 HCl HBr H2O or HOCl HOBr across the double bond Clue C C or C C and H2 Cl2 Br2 HCl HBr H2O add H2 Pd Rh C alkene H2 Pt graphite alkane H Pt Pd Rh or Cgraphite H2 H add Cl 2 or Br2 alkene X2 dihaloalkane Cl Cl2 Cl add HCl HBr can yield multiple products alkene HX haloalkane H Cl HCl H Cl add H2O can yield multiple products 2SO 4 alkene H2O H alcohol OH H2O H H2SO4 H OH ALKYNES ADDITION same reactions as alkene addition can be 2 separate steps or 1 combined step Pd Rh C Pt Pd Rh C alkyne H2 Pt graphite alkene H2 graphite alkane or Pd Rh C alkyne 2H2 Pt graphite alkane H Cl HCl Cl H H H H H Cl HCl Cl H Cl H Cl Cl Cl 2HCl Note during the alkyne addition rxn it s generally not possible to isolate the alkene product so it s more accurate to show H H Cl 2HCl H H Cl H Cl H Cl Cl Cl 3 AROMATIC SUBSTITUTION substitute NO2 Cl Br or CH3 CH2CH3 for an aromatic H not all of these reactions are always covered Clue FeCl3 FeBr3 AlCl3 and Benzene substitute NO2 NO2 HNO3 H2SO4 H2O NO2 NO2 substitute Cl Br Cl2 FeCl3 adds Cl Br Br2 FeBr3 HBr Br Br substitute CH3 or CH3CH2 CH3Cl adds CH3 CH3CH2Cl adds CH2CH3 CH3Cl AlCl3 HCl 4 REDOX alcohols aldehydes ketones carboxylic acids Clue K2Cr2O7 KMnO4 LiAlH4 NaBH4 oxidizing agents K2Cr2O7 with H2SO4 KMnO4 with H2SO4 oxidation num electrons O H reducing agents LiAlH4 abbreviated LAH NaBH4 oxidation num electrons O H H2SO4 1 alcohol KMnO4 or K2Cr2O7 aldehyde KMnO4 or K2Cr2O7 LiAlH4 or NaBH4 H2SO4 carboxylic acid LiAlH4 or NaBH4 OH O K2Cr2O7 H2SO4 O K2Cr2O7 H2SO4 OH LiAlH4 LiAlH4 Note During the oxidation of a 1 alcohol to a carboxylic acid it s generally difficult to stop at the aldehyde product Some instructors may use the word excess next to the K2Cr2O7 or KMnO4 reagent to signify the reaction goes to the carboxylic acid and when no excess is used it can mean to stop at the aldehyde product Note what your instructor does to clarify this issue 2 alcohol KMnO4 or K2Cr2O7 H2SO4 ketone LiAlH4 or NaBH4 K2Cr2O7 H2SO4 K2Cr2O7 OH LiAlH4 H2SO4 3 alcohol KMnO4 or K2Cr2O7 HO K2Cr2O7 H2SO4 no reaction O no reaction H2SO4 no reaction A Way to Think About Chemical Reactions OH K2Cr2O7 H2SO4 Question 1 What functional group does the reactant contain 2 What reactions can this functional group undergo 3 What reagents catalysts are present Primary 1 alcohol Oxidation combustion K2Cr2O7 H2SO4 4 What reactions do the reagents catalysts correspond with K2Cr2O7 oxidizing agent 5 What reaction will this molecule undergo with the reagents catalysts present 6 Write the products and change only the functional group s that undergo this reaction leave all other functional groups atoms unchanged oxidation OH K2Cr2O7 OH O O H2SO4 OH Answer 1 Which of the following statements is false a Methane will have a lower boiling point than methanol b Ethylene glycol CH2 OH CH2 OH will have a lower boiling point than ethanol c …