organic chem review

Question 1

general info on organic compounds

Answer 1

more than 10m or compounds have been discovered and 90% are organic compounds
chemists will isolate and identify chemicals from natural products and then synthesize these or similar chemicals for various purposes
examples of sythetically produces chemicals are gasoline, nylon and polyester
carbon compounds include DNA, enzymes, proteins and plastics

Question 2

carbon componyds

Answer 2

carbon atoms bond easily to one anotehr to form rings, long chains and complex branched chain molecules
no other element possesses this property
the max bonds that can be made with c to satisfy octet is 4
the bond angles between any to c in an alake chain is 109.5 with the exception of cyclical structures

Question 3

Hydrocarbons

Answer 3

hydrocarbons- structures that consist of carbons and hydrogens only bonded together
just c and h atoms
alkane is c-c, alkene is c=c and alkyne is tripple bond
alkanes are saturated while other hydrocarbons are unsaturated as they have multiple bonds or rings
alkanes are aliphatic: long straight chains
ch2 repeats in alkanes are called homologous series

alkanes are hydrocarbons containing single bonds, formula CnH2n+2
alkene are hydrocarbons containing double bonds, formula CnH2n
alkynes are hydrocarbons containing triple bonds, formula CnH2n-2
cyclical are hydrocarbons connected to each other in a chain, formula CnH2n

(# used to specify location of db or tb)

Question 4

alkyl branches

Answer 4

branches can be alkanes like methyl, ethyl etc. and are numbered by saying #-alkyl alkane
some branches are not straight chains for example isopropyl, sec butyl, tertbutyl and isobutyl which are also names #-alkyl alkane but when naming iso counts but not sec or tert

Question 5

halide branch

Answer 5

halides = f,cl,br and i
functional group name is halo
naming is changed from instead of ine ending of halogen to o ex.1-chlorocyclobutane
gets priority over alkyl groups
name is alpha order
named #halo alkane

Question 6

aromatic compounds

Answer 6

derivatives of benzne
the e are delocalized so they can move around
have formula of c6h6
it was first isolated by micheal faraday 1825
colourless sweetish smelling liquid
kekule proposed a ring structure with alternating sb and db
planar molecule
bond lengths are all same (139pm c-c are 148 while c=c is 134
when benze in branch then called phenyl
if 2 branches on benze sometimes follow ortho (1,2), meta(1,3) and para (1,4) but its not iupac

common ones are phenol, toluene, analine, benzenaldehyde, benzanoic acid and benzenamide

Question 7

functional groups

Answer 7

organic functional groups may bond with a carbon of an aliphatic compound to proidce a compound with a new name but also physical and chem properties that are unique to the functional group

Question 8

alcohols

Answer 8

functional group name hydroxyl
alcohol contain -oh so r-oh where r is alkyl group
presence of oh means that hydrogen bonding is possible
isomers are possible with alcohols containing more than 2 c
oh branch more important than halo and alkyl
ending name with ol (alkan-#-ol)
hydroxyl gets priority if db or tb present
called hydroxy if its a branch
primary alcohol = r-ch2oh
secondary = rr-ch-oh
tert = rrrc-oh

Question 9

ether

Answer 9

related to anesthesia
2 hydrocarbons connected by an o and have formula r-o-r
mostly used for solvents in organic reactions
named #-alkoxy alkane

Question 10

aldehydes

Answer 10

functional group carbonyl
r-hc=o or r-cho
terminal group so found at start of hc chain
alkanAL

Question 11

ketones

Answer 11

functional group of carbonyl
are like aldehydes but the carbonyl group is found in middle of chain so written as rrc=o
ketones like aldehydes don’t exhibit h bonding (ldf or d-d only)
there r commons names for ketones like acetone which is key ingredient in nail polish remover
named alkan-#-one

Question 12

carboxylic acid

Answer 12

functional group carboxyl
distincly acidic (turn litmus red)
general formula rcooh
carbon with double bond to o and bond to oh on terminal carbon
alkanoic acid

Question 13

amines

Answer 13

functional group amine
amines smell fishy
derivative of amonia with alkyl groups attached to n atom
primary secondary and tert amines based on r groups attached to n
named n-alkyl alkan-#-amine

Question 14

esters

Answer 14

functional group ester
used in food as flavouring agents and in perfumes for scenting
deravitaves of carboxylic acid where oh group turned into or so r-coor
made from reacting ca with alcohol
count c chain from c=o to opp way of the single o
named alkyl alkanoate

Question 15

amides

Answer 15

functioanl group carboxamide
components of tylenol and fertilizer
formed by creating ca with amine group
named n-alkyl alkanamide

Question 16

nitrile/cyano

Answer 16

found in inorganic chem
named #-cyano alkane

Question 17

nitro

Answer 17

found in explosives
named #-nitro alkane

Question 18

bp and mp of alkanes

Answer 18

pure hydrocarbon are non polar so have ldf
the linear rise in mp as the chain elongates is due to the increases in intermolecular attractions (stronger hand holding) due to ldf and increase in atomic weight
bigger the molecules the higher bp and mp because stronger hand holding so need more energy to melt/boil

Question 19

isomers

Answer 19

isomers are compounds with the same molecular formula but different structures
- structural isomers: isomers that differ in the bonding arrangement and connectivity of atoms (same formula but diff arrangement in space) –> to draw isomers first identify if alkane, alkene or alkyne and then name as u draw to make sure u do not repeat stuff, generally its alkene and cyclostructure, ether and alcohol, ester and ca and ketone and aldehyde
- steroisomers: isomers that have the same connectivity but differ in the spatial (3d) arrangement of atoms
- geometric isomers: stereoisomers that differ in relative orientation of substituents, found in alkene or cyclostructure because the db does not allow for rotation around the bond due to the pi-bond so you can specify location of groups around the db (if identical then cis on same side or trans on opp sides. if diff groups on db then e for priority on diff sides and z for priority on same sides (priority assigned by higher atomic number, based on cip rules. ez can be used for everything but cis and trans only for identical)
- enantiomers or optical isomers: stereoisomers that are chiral, non-superimposible on a mirror image. a chiral molecule is any molecule containing a c with 4 different attached groups is capable of existing as 2 diff isomers that are mirror images
chiral=mirror images=non superimposible= enantiomers
* means optically active
enantimers interact with light differently –> polarized light means going in one direction –> a polarimeter is used to measure the optical rotation of molecules in a solution. the tube contains an optically active substance in a solution which causes the plane or polarized light to rotate and then the analyzer rotates until no light goes through and the angle is then measured to determine the optical rotation of the optically active substance. compounds that rotate the light towards the right is called dextrorotatory and to the left is called levorotatory. if its 5050 mixture of d and l then its a racemic mixture so the polarized light is 0

for questions abt chiral carbons dra the compound out and identify the chiral c and if chiral then draw the enantiomer (* indicates optically active)

Question 20

Types of reactions

Answer 20

• Addition reactions: an atom or group is added across a double or triple bond so getting rid of unsaturation. You follow M. hydrogenation (usually used to covert vegetable oils into margarine and cooking fats): h is added to bond, hydrhalogenation: addition of HX, halogenation: addition of X2, hydration: addiction of HOH, benzene cant undergo addition as it wants to keep its double bonds

Substitution reaction: an atom or group replaces another atom in a molecule. alkane: substitution of an alkane with halide is possible in presence of a catalyst (hv), benzene: only undergoes substitution (uses Fe for x2, H2SO4 for HNO3 and al for r-cl), amine: reaction of an alkyl halide with amonia in presence of NaOH, alkyl halide: reaction of an alcohol with concentration HX, alcohol: a reaction of an alkyl halide with concentration NaOH

Elimination Reactions: something is removed in a molecule to create a multiple bond. you need an adjescent h to remove. cracking (used in petroleum industry): creating alkane to alkene by using heat, dehydration: removal of water from an alcohol (needs catalyst H2SO4), dehydrohalogenation remove of an h and x by using NaOH conc

Oxidation reaction: loss of e. carbon atom forms more bonds to o or less to h. catalyst is KMnO4, 1 degree alcohol becomes aldehyde or ca and 2nd degree become keton while 3rd degree cant oxidize

reduction: gain of e. carbon forms more bonds to h or less to o . catalyst NaBH4. aldehyde and ca become reduced to 1 degree alchols while ketone gets reduced to 2nd degree alcohol

condensation reaction: removal of h2o in the process of joining two molecules together. you need H+ as a catalyst. 2 alchols become etehr, alcohol and ca become ester and amine and ca become amide

hydrolysis: adding h2o to break molecule into its 2 things. ether to 2 alchols, ester to ca and oh, amide to ca and amine

combustion: extreme oxidation. becomes co2 and h2o. usually ? + o2 gives co2 and h2o

acid base reaction: acid + base gives water and salt or creates ammonium (nh4 with plus charge)

Question 21

retrosynthesis

Answer 21

just puting togetehr the above/previous reaction to get to different molecules

rmbr that H+ is for condenstaion and hydrolysis, hv for substitution in alkane, temp for cracking, fe H2SO4 and al in benzene, NaOH for alkane sub in amine, HCL or NaOH to switch between alcohol or alklhalide, h2so4 for removal of water, kmno4 for oxidation and nabh4 for reduction

Question 22

Polymer

Answer 22

polymers are long chains of repeating molecules. each repeating unit is called a monomer

polymers are named by adding poly prefix and monomer name

There are branched and straight chain polymers which can be held by covalent bonds or ldf
- they are used in industry )teflon and plastic), in nature (starch and DNA), properties of polymers depends on what they are made of that is the monomer type, length of chain and shape of polymer chain. some polymers tend to form branches while other for straight chains(depends on functional group). straight chained polymer tend to pack well together compared to branched polymer meaning they are stronger. EX. low density polyethylene is branched and high density polyethylene is straightchained

Chemists have learned to synthesize alkanes with a desired melting points by controlling the length of the product chain. Chemical reactivity maybe similarly influenced by the presence of functional groups that can be arranged in chains along the molecule.

Polymerization is the chemical process of linking monomer units to produce a long chain of repeating unit called a polymer.

For example:
Polyethylene bags are made of repeating units of ethane.
Naming this polymer: Polyethene.

Two Types: Addition and Condensation Polymers

Addition polymerization: reacting multiple monomers with double bonds to produce a polymer (or addition to a double bond) (db flips out to join, if creating 4 monomers in the polymer then 8 c total)

Example: Ethene (bonding is accomplished by opening unsaturated bonds between the carbon atoms in the molecules.)

Note: Replacing one of more of the H atoms on the ethene molecule with groups like -F, -Cl, -CH3, -COOH3. Synthetic polymers with trades names such as Teflon, Saran, Lucite, and Plexiglass result.

Condensation polymerization: reacting monomers such that an ester bond or an amide bonds is produced along with water.

• Condensation polymers of esters are called Polyesters. (Dacron: monomer contains a two carboxylic acid groups which reacts with a monomer containing two alcohol groups)
• Condensation polymers of amides are called Nylons or Polyamides. (In 6,6 Nylon: each monomer contains two amine groups which reacts with another monomer contain two carboxylic acid groups)
• Another example found in nature is the linking of amino acids to form a polypeptide chain. If the chains are very long, they are called proteins. Amino acids contain both an amine group and a carboxyl group. The simplest amino acid is glycine.
  Linking two amino acids together by an amide bond is referred to as a peptide bond.
• Sugars also undergo condensation reactions to produce various types of sugars with different properties.