Organic chemistry - 2

Question 1

what is a haloalkane?

Answer 1

saturated compounds with one or more hydrogens replaced by halogen atoms (e.g F, Cl, Br, I)

Question 2

what are the three classes of monohaloalkanes?

Answer 2

primary, secondary, tertiary

Question 3

what are the rules for naming a haloalkane?

Answer 3

• halogen atom ( more than one - di, tri, tetra)
• name of compound based on longest unbranched chain
• show position

Question 4

what type of reaction will haloalkanes undergo?

Answer 4

nucleophilic substitution reactions

Question 5

Haloalkane + alkali -> ?

Answer 5

alcohol (+salt)

Question 6

haloalkane + cyanide -> ?

Answer 6

nitrile (+salt)

Question 7

haloalkane + alkoxide -> ?

Answer 7

ether (+salt)

Question 8

how is an alkoxide made?

Answer 8

alcohol + alkali metal -> metal alkoxide + hydrogen

Question 9

what are the steps of a nucleophilic substitution reaction of tertiary and some secondary haloalkanes?

Answer 9

step 1 - slow formation of carbocation

step 2 - fast attack by nucleophile

Question 10

what type of reaction is a nucleophilic substitution reaction of tertiary and some secondary haloalkanes?

Answer 10

Sn1

Question 11

what type of reaction is a nucleophilic substitution reaction of primary and some secondary haloalkanes?

Answer 11

Sn2

Question 12

what are the steps of a nucleophilic substitution reaction of primary and some secondary haloalkanes?

Answer 12

step 1- slow attack by nucleophile

step 2 - formation of intermediate

Question 13

what helps to stabilise Sn1 reactions?

Answer 13

alkyl groups around the cation

Question 14

what is the term used to describe the stability in Sn1 reactions?

Answer 14

inductive stabilisation

Question 15

what allows the nucleophile to attack in Sn2 reactions?

Answer 15

absence of bulky alkyl groups

Question 16

which type of haloalkane has the most stable carbocation?

Answer 16

tertiary

Question 17

what is reduced in Sn2 reactions?

Answer 17

steric hindrance

Question 18

haloalkane + base -> ?

Answer 18

alkene

Question 19

what catalyst is used in an elimination reaction to produce an alkene

Answer 19

KOH in ethanol

Question 20

what makes up an sp2 orbital?

Answer 20

one s + two p orbitals

Question 21

unhybridised p orbitals are ? to the plane of the molecule

Answer 21

perpendicular

Question 22

what is a π (pi) bond?

Answer 22

sideways overlap of two parallel atomic orbitals

Question 23

what is a C-C bond made of?

Answer 23

1σ

Question 24

what is a C=C bond made of?

Answer 24

1σ + 1π

Question 25

what is a C-C triple bond made of?

Answer 25

1σ + 2π

Question 26

what is a structural isomer?

Answer 26

same molecular formula, different structure

Question 27

what is a stereoisomer?

Answer 27

- identical molecular formula - atoms bonded together in same order - different arrangement of atoms in space

Question 28

in terms of shape, stereoisomers are described as being ?

Answer 28

non-superimposable

Question 29

what is a geometric isomer?

Answer 29

stereoisomers due to lack of free rotation around a bond

Question 30

what is the term used to describe when atoms are on the same side of double bond in a geometric isomer?

Answer 30

cis

Question 31

why would a geometric isomer be described as trans?

Answer 31

atoms are across the double bond

Question 32

do geometric isomers have similar or different physical properties?

Answer 32

different physical properties (eg B.P)

Question 33

name four alkene addition reactions

Answer 33

- hydrogenation - halogenation - hydrohalogenation - hydration

Question 34

hydrogenation: alkene + ? -> ?

Answer 34

alkene + hydrogen -> alkane

Question 35

halogenation: alkene + ? -> ?

Answer 35

alkene + halogen -> dihaloalkane

Question 36

hydrohalogenation: alkene + ? -> ?

Answer 36

alkene + hydrogen halide -> monohaloalkane

Question 37

what is markovnikovs rule?

Answer 37

hydrogen adds onto the carbon that already has the larger number of hydrogens

Question 38

Hydration: alkene + ? -> ?

Answer 38

alkene + water -> alcohol

Question 39

what is the catalyst needed fro hydration?

Answer 39

acid catalyst: c.H2SO4