3.3.11 Amines

Question 1

What is a amine

Answer 1

One or more H+ replaced by an alkyl or aryl group

Question 2

what are the amines

Answer 2

primary - NH2
secondary - NH
tertiary - N

Question 3

what is a quarternary amine

Answer 3

an ammonium salt

Question 4

give a name example of a primary amine

Answer 4

methylamine
ethylamine

Question 5

Give a name of a secondary amine

Answer 5

dimethylamine
n - methyl propylamine

Question 6

name a tertiary amine

Answer 6

trimethylamine

Question 7

benzene and amine

Answer 7

phenyl amine

Question 8

properties of amines

Answer 8

shape - pyramidal 107 not 109.5 has lone pairs

fishy smell -> tri amines produced when proteins decompose

solubility -> primary up to 4C
not verry soluble water (as hydrogen bonds) and alcohol

Reactivity -> 1. lp used form bonds with H+ - base
2. acts as a nucleophile to bond with a electron deficient carbon

Question 9

Boiling point of amines

Answer 9

bp - the c is partially positive - n is partially negative
-> polar molecule
primary amine have H+ bonds -> not verry strong -> N electronegative -> short gasses

Question 10

what kind of base is a amine

Answer 10

Bronsted-Lowry base

accept a H+

Question 11

alkylamines reactions with acids (eg HCl)

Answer 11

creates an ammonium salt

the ammonium ion and a cl-

woks for phenylamine despite relatively insoluble

Question 12

What is the inductive effect

Answer 12

alkyl groups release electrons away from the alkyl group towards the N.

inductive effect increases the electronegativity of the N - makes it a better electron pair donor - more reactive

Question 13

order of the base strengths

Answer 13

ethylamine -> ammonia -> phenylamine

Question 13

comparing comparing base strengths explained

Answer 13

primary - one inductive effect - better than NH4 because of the inductive effects

secondary - 2 inductive effects = stringer then primary

tertiary - not stronger than 2 as less soluble in H20 <- less H+ bonding

aryl amines -> withdraw electrons from the N <- lp of electron overlap with the delocalization system

n weaker electron pair donor = decrease attractivity to the H+

Question 14

what is an aliphatic amine

Answer 14

a striaght chain amine

Question 15

what reaction is undergone when a haloalkane and ammonia react together

Answer 15

nucleophilic substitution of the halide by NH2

Question 16

Stages of the nucleophilic substitutions equations

Answer 16

NH3 + RX -> (RNH3)+ x-
(RNH3)+ x- -> NH3 -> RNH2 + (NH4)+ X-

Question 17

quaternary amonia compounds uses

Answer 17

Quaternary ammonia compounds used in the manufacture of hair and fabric conditioner

Cationic surfactants - in aq solutions ins cluster with their charged ends in water and hydrocarbon tails on surface

Wet fabrics and hair pick up neg charge - positive charges of the cations attract them to wet surface - prevents build up of static electricity