6.2 NITROGEN COMPOUNDS,POLYMERS & SYNTHESIS

Question 1

State what determines primary,secondary and tertiary name for amines

Answer 1

• The number of alkyl chains/groups on the nitrogen

Question 2

State the prefix for a secondary amine (e.g methyl propylamine)

Answer 2

N-methyl propylamine

Question 3

State the prefix for a tertairy amine (e.g diethyl propylamine)

Answer 3

N,N-diethyl propylamine

Question 4

Explain how amines are bases in terms of bronsted-lowry and lewis

Answer 4

• The nitrogen atom has a lone pair of electrons which accept H⁺ protons
• Therefore, amines are weak bases that react with dilute strong acids to form salts

Question 5

Alkyl amine + acid –>

Answer 5

Alkylammonium salt

Question 6

Reaction/conditions for amine with HCl (e.g ethylamine)

Answer 6

Question 7

Reaction/conditions for amine with HNO3 (e.g dimethylamine)

Answer 7

Question 8

Reaction/conditions for amine with H2SO4 (e.g propylamine)

Answer 8

Question 9

Reaction/conditions for aromatic amine preperation

Answer 9

Question 10

Explain why in the preperation of aromatic amines that strong NaOH/alkali is used afterwards.

Answer 10

• To remove the excess HCl left by neutralising it

Question 11

Reaction/conditions for the preperation of primary aliphatic amines (2 STEP)

Answer 11

Question 12

State and explain the effect of using excess NH3 in primary aliphatic amine preperation

Answer 12

• Excess ammonia can limit further substitution reaction
• However, excess ammonia maximises the yeild of primary amine product (because its a reversible reaction)

Question 13

Reaction/conditions for the preperation of secondary aliphatic amines

Answer 13

Question 14

Reaction/conditions for the preperation of tertiary aliphatic amines

Answer 14

Question 15

Draw the general strcuture of a α-amino acid

Answer 15

RCH(NH₂)COOH

Question 16

Define zwitterion

Answer 16

• The formation of an internal salt as both functional groups exchange a proton to reach an isoelectric point

Question 17

Define isoelectric point

Answer 17

• When there is no net electrical charge due to the zwitterion having an internal balance of charge
• pH 6.5

Question 18

Draw and explain the effect of low pH/acidic conditions on a zwitterion

Answer 18

Question 19

Draw and explain the effect of high pH/basic conditions on a zwitterion

Answer 19

Question 20

State the four reactions of an amino acids carboxyl group (COOH)

Answer 20

Question 21

State the reaction of an amino acids amine group (NH2)

Answer 21

Question 22

State what determines primary and secondary name for amides

Answer 22

• The number of overall alkyl chains/groups attached to the amide group

Question 23

Define optical isomerism

Answer 23

• Two non-superimposible mirror images about a chiral centre

Question 24

Draw the optical isomers of an amino acid

Answer 24

Question 25

State the **four** ways of **extending** the **carbon chain length**

Answer 25

Question 26

Reaction/conditions/mechanism for **haloalkanes** with **KCN**

Answer 26

Question 27

Reaction/conditions/mechanism for **carbonyl compounds** with **NaCN**

Answer 27

Question 28

Reaction/conditions/mechanism for **freidel-crafts alkylation**

Answer 28

Question 29

Reaction/conditions/mechanism for **freidel-crafts acylation**

Answer 29

Question 30

State the **two** reactions of **nitriles**

Answer 30

Question 31

Reaction/conditions for the **reduction** of **nitriles**

Answer 31

Question 32

Reaction/conditions for the **hydrolysis** of **nitriles**

Answer 32

Question 33

Define **condensation polymerisation**

Answer 33

- When **two monomers** with **different functional groups** react to form a **polymer** and **water**

Question 34

State the **two** **di-monomer** ways of forming **poly(esters)**

Answer 34

1) **Dicarboxylic acid** + **diol** ⇌ **poly(ester)** + **water** (low yeild, requires H2SO4 catalyst) 2) **Diacyl chloride** + **diol** → **poly(ester)** + **HCl** (corrosive fumes)

Question 35

State the **two** **di-monomer** ways of forming **poly(amides)**

Answer 35

1) **Dicarboxylic acid** + **diamine** ⇌ **poly(amide)** + **water** (low yeild, requires H2SO4 catalyst) 2) **Diacyl chloride** + **diamine** → **poly(amide)** + **HCl** (corrosive fumes)

Question 36

Explain why in the formation of **poly(esters)** and **poly(amides)**, **diacyl chlorides** are chosen over **dicarboxylic acids**

Answer 36

1) **Dicarboxylic acids** require the **strong acid catalyst H2SO4** 2) **Dicarboxylic acids** produce a **low yeild** of **polymer** because its a **reversible reaction**

Question 37

Draw the **two structural** formations of **poly(esters)**

Answer 37

Question 38

Explain why **poly(esters)** are **biodegradeable**

Answer 38

- Their **ester group/link** can be **hydrolysed**

Question 39

Draw the **two structural** formations of **poly(amides)**

Answer 39

Question 40

Draw the **acid-base hydrolysis** of **poly(esters)**

Answer 40

Question 41

Draw the **acid-base hydrolysis** of **poly(amides)**

Answer 41

Question 42

State the **two** methods of **purifying** an **organic solid**

Answer 42

1) **Filtration** under **reduced pressure** 2) **Re-crystallisation**

Question 43

State the method used to **measure purity**

Answer 43

- **Measuring melting points**

Question 44

State what