AMINES

Question 1

Amine

Answer 1

an amine is derived from ammonia molecule containing a nitrogen atom where hydrogen is replaced with an organic group.

Question 2

different types of amine

Answer 2

primary, secondary, tertiary and quaternery

Question 3

aliphatic amine

Answer 3

non aromatic amines are called aliphatic amines.

Question 4

cationic surfactants

Answer 4

quaternery ammonium salts with long hydrocarbon tail are called cationic surfactants.
- quaternery ammonium salts are used to make cleaning products like shampoos, detergents etc.

Question 5

what are quaternery ammonium salts made of

Answer 5

positive ends attracted to negative ions.
example of quaternery ammonium salt will be tetra methyl ammonium chloride.

Question 6

how does cationic surfactants work on grease

Answer 6

• their non polar tail is attracted to oil or grease and their polar head is attracted to water which doesnt allow both of them to mix and hence removes grease from clothing.

Question 7

why are cationic surfactants used in shampoos and hair conditioner and fabric washing

Answer 7

because cationic surfactants have a positively charged ammonium ion which is attracted to negatively charged fibre and hair

Question 8

amine as a base

Answer 8

• amine acts as a base because the lone pair pf electrons allows them to accept a proton, proton acceptors are base.

Question 9

how is proton binding to amine

Answer 9

via a dative covalent bond. electrons are originating from nitrogen lone pair.

Question 10

strength of base depends on

Answer 10

1. availability of lone pair of electrons on the nitrogen
2. higher the electron density - more readily avaiable electrons.

Question 11

what is electron density depending on

Answer 11

electron density depends on type of r group attatched to nitrogen.

Question 12

order of base strength in amine

Answer 12

primary aliphatic amines > ammonia > aromatic amines

Question 13

why are aromatic amines less basic?

Answer 13

• because benzene is an elextron withdrawing group ( delocalised electron ring) and it pulls electron from the nitrogen into the ring structure .
• electron density of nitrogen decrerases so there is less availability of lone pair hence aromatic amines are more basic.

Question 13

why are primary aliphatic amines more basic

Answer 13

• because primary aliphatic amines contain an alkyl group
• alkyl group pushes away the electrons into the nitrogen .
• electron density at nitrogen increases so there is an increased availability of lone pairs
• thus making primary aliphatic amines more basic.

Question 13

nucleophiles

Answer 13

amines are nucleophiles with lone pairs and loves nucleus

Question 13

process of making primary aliphatic amines

Answer 13

1. reacting halogenoalkane with excess ammonia
2. reducing nitriles

Question 14

forming primary amines bybreducing nitrile

Answer 14

reducing nitriles using a nickel catalyst and hydrogen gas.

Question 14

reacting halogenoalkane and excess ammonia produces

Answer 14

primary aliphatic amine and ammonium chloride salt.

Question 14

disadvantage of rxn between halogenoalkane and excess ammonia

Answer 14

1. along with primary amines, secondary , tertiary and quaternery salts are also produced making an impure product.
2. primary amine still has lone pair which can react with remaining halogenoalkane to produce secondary amines further and tertiary and quaternery salts.

Question 14

catalytic hydrogenation

Answer 14

production of primary amines by reducing nitrile using hydrogen gas and a nickel or platinum catalyst

Question 15

conditions for catalytic hydrogenation

Answer 15

1. nickel as a catalyst and high temperature and pressure.

Question 16

reduction for aliphatic amine

Answer 16

using a strong reducing agent lialh4 and dilute acid.
- dissolved in dry non aqueous solvent such as dry ether.

Question 17

how do we make aromatic amines

Answer 17

by reducing nitro benzenes

Question 18

where are aromatic amines used

Answer 18

dye stuffs and pharmeceuticals

Question 19

why is aromatic amines made under reflux

Answer 19

• because they are volatile compounds and we dont wanna lose any reactants or products