nucleophilic substitution reactions

Question 1

define nucleophile

Answer 1

a nucleophile is a species with a lone pair of electrons, which it donates to a delta positive carbon, forming a new covalent bond.

Question 2

define substitution reaction

Answer 2

substitution reactions are where one atom or group in a molecules gets replaced by another atom or group

Question 3

define nucleophile

Answer 3

a nucleophile is a species with a lone pair of electrons, which it donates to a delta positive carbon forming a new covalent bond

Question 4

define substitution reaction

Answer 4

substitution reactions are when one atom or group in a molecule gets replaces by another atom or group

Question 5

name the conditions and reagents needed for the reaction of an alkane and OH- ions

Answer 5

reagents: NaOH (aq) which provides the OH- ions (Na+ are spectator ions)
conditions: heat under reflux

Question 6

what is reflux?

Answer 6

Reflux is where a liquid reaction mixture is boiled in a flask connected to a vertical condenser. this is used when the mixture needs heating for a while as it prevents loss of reactants and products as vapour, the compounds continuously evaporate then condense and drip back down into the mixture.

Question 7

describe an alkanes reaction with water

Answer 7

water can act as a nucleophile as the oxygen has a lone pair that it can donate and is delta negative. But it is a weaker nucleophile s=than OH- ions (as water does not have a full - charge) the reaction is very slow, as with OH- the product is an alcohol

Question 8

how many stages are there in a reaction between an alkane and a water molecule?

Answer 8

Three.
there is an intermediate stage, since the O still has 2 hydrogens bonded so it needs to break the bond between the O and H before the reaction is complete

Question 9

what are the reactants and conditions required for an alkane to react with ammonia (NH3)?

Answer 9

since ammonia is a nucleophile without a full minus charge, the reaction is vigorous.
reactants: concentrated ammonia solution
conditions: heat in a sealed tube

Question 10

how many stages does a reaction between ammonia and an alkane have?

Answer 10

similar to water, an alkane and ammonia reacting have 3 stages. this is because there needs to be a bond broken between the N and one of the three H

Question 11

what’s NH2 group called?

Answer 11

an amine