Functional Groups

Question 1

Carbon-oxygen bonding

Answer 1

form covalent bonds via hybrid orbitals
requires 2 extra 2e- to fulfil the octet rule

can bond to carbon via a single bond- form a tetrahedral arrangement around oxygen

can form double bonds
in sigma portion have a pair of e- that also form trigonal arrangement
leave unhybridised p orbital to form pi bond

Question 2

alcohols

Answer 2

hydroxyl group -OH
primary, secondary or tertiary

Question 3

aldehydes

Answer 3

terminal carbon group -CHO
C always =O
always at end of molecule
carbonyl group has the lowest possible number

Question 4

ketones

Answer 4

carbonyl group >C=O
never at the end of the chain
functional group is always in the middle

Question 5

carboxylic acids

Answer 5

terminal carbonyl and hydroxyl group -COOH
alway at end of the chain

Question 6

ethers

Answer 6

O atom connected to 2 alkyl or aromatic groups
name both sides of chain next to O atom

Question 7

esters

Answer 7

derived from carboxylic acid
name on both sides of the functional group
O in middle of the chain attached to =O

Question 8

Functional group + OH group

Answer 8

use prefix -hydroxy

Question 9

carbon-nitrogen bonding

Answer 9

bind via hybrid orbitals
form covalent bonds to C atoms through hybrid orbitals
requires 3e- to fulfil octet rule

Question 10

amines

Answer 10

contain single bonded nitrogen
primary- N can be at the end of the molecule
secondary- N in the middle of the chain
tertiary- N bound to 3 different C atoms

Question 11

imines

Answer 11

possesses a C=N double bond

Question 12

nitriles

Answer 12

possesses a C-N triple bond
triple bonds can be toxic

Question 13

amides

Answer 13

comprise of a carbonyl group -C=O attached to an amine group
can be primary, secondary or tertiary

Question 14

amino acids

Answer 14

contain a primary amine (-NH2) and carbonyl (-COOH) group
important as its a peptide bond

Question 15

shape of organic molecules

Answer 15

e- in different orbitals repel each other
mutual repulsion will much the molecular orbitals as far apart as possible

tetrahedral arrangement of 4 bonded e- pairs

reactivity often dependent on molecular shape

Question 16

sp3 hybridised atoms

Answer 16

single bonds
tetrahedral geometry of e- pairs

Question 17

sp2 hybridised atoms

Answer 17

contains double binds
trigonal planar geometry of e- pairs
trigonal arrangement to minimise e- repulsions

Question 18

sp hybridised atoms

Answer 18

contains triple bonds
linear arrangement of e- pairs

Question 19

what are the 3 types of isomerism?

Answer 19

structural
geometric stereoisomerism
optical isomerism

Question 20

structural isomers

Answer 20

alcohols:
boiling points different in alcohols
alcohols can be oxidised
reactivities different as well as boiling points

ethers:
react differently to alcohols

Question 21

optical isomers

Answer 21

amino acids exhibit optical isomerism
central C is a chiral centre- bound to NH2, COOH and H

exist as enantiomers
rotate the plane of polarised light by equal amounts in opposite directions

Question 22

biological systems and enantiomers

Answer 22

very selective
enzyme reactions are often enantioselective

chemical cannot tell which is present, cannot separate them, biologically act different

Question 23

chiral centres

Answer 23

cannot be a double bond
end carbon cannot be chiral

Question 24

link between electronic configuration, orbital hybridisation & molecular shape

Answer 24

C, O and N form bonds through hybrid orbitals
sp3, sp2 or sp
single, double or triple bonded
tetrahedral, trigonal or linear