Organic Chemistry - (Amines, Amino Acids so far)

Question 1

Are amines soluble in water? If so why?

Answer 1

Amines are soluble in water due to hydrogen bonding.

Question 2

How can amines behave as bases?

Answer 2

The nitrogen has a lone pair which can act as a proton acceptor.

Question 3

What happens when amines react with acids?

Answer 3

A salt is produced. It also removes the smell of the amine.

Question 4

How would you identify the type of amine or amide?

Answer 4

If there are 2 Hydrogens attached to the Nitrogen, it is PRIMARY.

If there is 1 Hydrogen attached to the Nitrogen, it is SECONDARY.

If there are NO Hydrogens attached to the Nitrogen, it is TERTIARY.

Question 5

How can amines be prepared from haloalkanes?

Answer 5

Haloalkanes react with alcoholic ammonia under pressure and reflux.
Ammonia is the nucleophile and an amine (or its salt) is produced.

Question 6

When producing a amine from a haloalkane, why is the amine produced also a nucleophile?

Answer 6

The amine produced is also a nucleophile because the nitrogen has a lone pair. It can attack another molecule of halogenoalkane to produce a secondary amine. This can repeat to produce tertiary and quarternary amines.

Question 7

Give an example of a haloalkane.

Answer 7

C2H5Br

Question 8

What conditions are needed when reducing aromatic nitro compounds to aromatic amines?

Answer 8

Concentrated HCl
Sn
Reflux

Question 9

How would you turn Nitrobenzene to Phenylamine?

Answer 9

Nitrobenzene with conc HCl and Sn.
Then NaOH(aq) to get Phenylamine.

Question 10

How do you get Nitrobenzene to eventually reduce to phenylamine?

Answer 10

Benzene with concentrated HNO3 and H2SO4

Question 11

What is the difference between an aromatic amine and an aliphatic amine?

Answer 11

Aromatic has a benzene ring, aliphatic doesn’t.

Question 12

Define (alpha) amino acids.

Answer 12

They have a carboxylic acid and an amine attached to the same carbon.

They are all on carbon 2.

Question 13

Define zwitterions.

Answer 13

Amino acids have an acidic and basic group therefore the acidic group (COOH) readily donates a proton to the basic group (NH2). This forms an internal salt which is a zwitterion.

Question 14

Why are amino acids amphoteric?

Answer 14

They can behave as both bases

Question 15

What is a isolectric point?

Answer 15

The pH at which an amino acid is in neutral overall. This is not necessarily pH 7.

Question 16

What happens when you add an acid or an alkali to glycine?

Answer 16

When an acid is added, glycine’s carboxylic acid doesn’t change but its amine has a positive charge.
eg.
NH2CH2COOH + HCl (aq) —–> Cl- N+H3CH2COOH

When an alkali is added, glycine’s amine stays the same but its carboxylic acid has a negative charge.
eg.
NH2CH2COOH + NaOH (aq) —–> NH2CH2COO- Na+ + H2O

Question 17

What functional group differs an amine from an amide?

Answer 17

Amides have a carbonyl group whereas amines don’t.

Question 18

Which type of amides are all proteins?

Answer 18

All proteins are secondary amides.