Organic Chemistry (Part 2)

Question 1

What are polymers?

Answer 1

Large organic molecules formed when similar molecules join together in long chains

Question 2

What is polymerisation?

Answer 2

The process of producing long chain molecules from small molecules

Question 3

What is addition polymerisation?

Answer 3

How monomers can join together to form very long chain molecules called polymers

Question 4

What is a monomer?

Answer 4

The small molecules that add together to make a polymer

Question 5

What is polythene?

Answer 5

Made by joining together 30,000 - 40,000 molecules of ethene (monomer).

Question 6

Properties and uses of polythene

Answer 6

Properties - light, flexible and resistant to attack by acids and alkalis.
Uses - cling film, plastic bags, bottles, buckets and basins

Question 7

Properties and uses of Polyvinylchloride (PVC)

Answer 7

Properties - tough, durable, waterproof and good insulator
Uses - electric cables, guttering, drain pipes, and umbrellas and window frames

Question 8

Advantages of plastics

Answer 8

Less dense than other materials.
Resistant to chemicals and water.
Extremely long lasting.

Question 9

Disadvantages of plastics

Answer 9

Addition polymers are non-biodegradable.
Surplus of plastics littering our oceans.
Kills aquatic life.

Question 10

Advantages and disadvantages of landfill

Answer 10

Advan - local treatment so less transport needed and landscape can be re-landscaped after use.
Disadvan - wastes land and polluting gases released.

Question 11

Advantages and disadvantages of incineration

Answer 11

Advan - less waste going to landfill and heat energy can generate electricity.
Disadvan - ash residue is toxic and polluting gases released.

Question 12

What is included in alcohols?

Answer 12

Methanol - CH3OH
Ethanol - C2H5OH
Propan-1-ol - C3H7OH - (-OH group on carbon number 1)
Propan-2-ol - C3H7OH - (-OH group on carbon number 2)
All liquids

Question 13

Properties of alcohols

Answer 13

General formula of CnH2n+1OH.
They can be regarded as being derived from an alkane by replacing a hydrogen atom by a hydroxyl functional group (-OH).
Ethanol is a water soluble (miscible) liquid.

Question 14

How to make ethanol?

Answer 14

Hydration of ethene.
Ethene + Water (Steam) - Ethanol

Question 15

Definition of clean fuel

Answer 15

Produces non-polluting products only (such as water) when it is burned/undergoes combustion e.g. hydrogen

Question 16

How to alcohols get oxidised?

Answer 16

By air - wine turned into wine vinegar (ethanol to ethanoic acid)
By acidified potassium dichromate (orange) - oxidising agent which oxidises some alcohols to carboxylic acids on warming.

Question 17

What is included in carboxylic acids?

Answer 17

Methanoic acid - HCOOH
Ethanoic acid - CH3COOH
Propanoic acid - CH3CH2COOH
Butanoic acid - CH3CH2CH2COOH
All liquids

Question 18

Properties of carboxylic acids

Answer 18

Most common is ethanoic acid or vinegar.
General formula is CnH2n+1COOH

Question 19

Why are carboxylic acids weak acids?

Answer 19

They are only partially ionised in solution

Question 20

How to distinguish between each organic family?

Answer 20

Alkane - doesn’t react to bromine, sodium carbonate or acidified potassium dichromate.
Alkene - reacts to bromine water.
Carboxylic acid - reacts to sodium carbonate.
Alcohol - reacts to acidified potassium dichromate.