C11

Question 1

What is a polymer ?

Answer 1

A substance made by joining thousands of small, identical molecules (monomers) in a repeating pattern.

Question 2

What type of monomer is used in an addition polymer ?

Answer 2

alkene monomers

Question 3

Why are addition polymers made up of the same atoms as their monomers ?

Answer 3

no other molecules are formed in the addition reaction, so all of the atoms in the monomer end up in the polymer.

Question 4

Define addition polymerisation.

Answer 4

• an alkene monomer’s carbon to carbon double bond is “opened up” by monomers adding across
• replaces double bond with single bond
• produces addition polymer with “backbone” of carbon atoms

Question 5

Why are polyesters biodegradable unlike addition polymers ?

Answer 5

microorganisms + bacteria can break down the ester links between molecules

Question 6

What are the conditions for forming a condensation polymer ?

Answer 6

• at least 2 functional groups present overall
• each monomer to have two of its own functional group
• in the reaction, a small molecule will be formed in addition to the condensation polymer

Question 7

How is a polyester formed ?

Answer 7

• dicarboxylic acid monomer (COOH functional group) + diol monomer (OH functional group)
• dicarboxylic acid monomer loses OH molecule, diol monomer loses one H atom
• lost atoms form H2O (water) molecule
• another OH and H are lost from either end so that the unit can bond to other repeating units
• dicarboxylic acid monomer + diol monomer –> polyester + 2H2O

Question 8

Name a polyester.

Answer 8

poly(ethyl ethanoate)
- ethanediol + hexanedioic acid –> poly(ethyl ethanoate) + water

Question 9

How is a condensation monomer unit represented ?

Answer 9

functional group -[rectangle]- functional group

Question 10

Describe a practical to make a condensation polymer such as nylon.

Answer 10

• put thin layer of diaminohexane in bottom of beaker
• pour thin layer of decanedioyl dichloride on top
• lift carefully the greyish film that forms and wrap it around a glass rod as a string
• this string is nylon
• HCl gas given off as the small molecule in the reaction

Question 11

What is a polysaccharide ?

Answer 11

polymer of monosaccharides (sugars like glucose, fructose, sucrose etc.)
include:
- starch
- cellulose
- glycogen
polysaccharides usually lose water as the small molecule during the condensation reaction

Question 12

What are the 3 atoms used in both mono and polysaccharides ?

Answer 12

• oxygen
• hydrogen
• carbon

Question 13

What is a polypeptide ?

Answer 13

A polymer made from amino acid monomers. When (multiple) polypeptides are folded up, these are proteins.

Question 14

What are the two functional groups present in amino acids ?

Answer 14

• amine group (NH2) which is BASIC
• carboxylic acid group (COOH) which is ACIDIC

these two monomers (specifically the OH and H molecules) can react (acid + base) to form water as the small molecule in the condensation reaction.

NOTE: there is also an “R” group on the bottom in the middle connected to the carbon atom which changes depending on which amino acid it is.

Question 15

What is a nucleotide ?

Answer 15

• monomer used to form DNA (deoxyribonucleic acid)
• forms water as the small molecule in the condensation reaction to form the polynucleotide (DNA)
• 4 different nucleotide monomers
• a nucleotide monomer is the sugar (deoxyribose) bonded to a phosphate group and a base
• ONLY THE BASE CHANGES BETWEEN THESE MONOMERS
• the 4 bases are A, T, C and G

Question 16

Describe the structure of DNA.

Answer 16

• double helix strands of polynucleotides
• strands held together by intermolecular forces between the base pairs on opposite strands (AT and CG)