5.4 - Organics 2

Question 1

What is the functional group for alcohols?

Answer 1

-OH

Question 2

Give 3 conditions required in the hydration of Ethene

Answer 2

-300C
-65 atm pressure
-Phosphoric acid (H3PO4 catalyst)

Question 3

Give 2 methods used to manufacture ethanol

Answer 3

1. hydration of Ethene
2. Fermentation of glucose

Question 4

2 advantages of Hydration of Ethene

Answer 4

1. makes pure ethanol
2. runs continuously

Question 5

2 disadvantages of Hydration of Ethene

Answer 5

1. requires lots of energy
2. uses non-renewable material

Question 6

Give 3 conditions required in the fermentation of glucose

Answer 6

-yeast (provides enzymes)
-30C (optimum temp for enzymes)
-anaerobic (prevents oxidation)

Question 7

2 disadvantages of fermentation of glucose

Answer 7

1. makes impure ethanol
2. must be done in individual batches

Question 8

2 advantages of fermentation of glucose

Answer 8

1. uses renewable material
2. doesn’t require lots of energy

Question 9

Give 3 ways ethanol can be oxidised

Answer 9

1. combustion
2. microbial oxidation
3. chemical oxidation

Question 10

Does ethanol combust completely or incompletely?

Answer 10

completely

Question 11

What is the result of ethanol complete combustion?

Answer 11

non-luminous blue flame

Question 12

How is ethanol oxidised by microbial oxidation?

Answer 12

micro-organisms use oxygen in air to oxidise ethanol into ETHANOIC ACID

Question 13

How is ethanol oxidised by chemical oxidation?

Answer 13

heat with: potassium dichromate, dilute sulfuric acid

Question 14

What is the colour change when ethanol is oxidised by chemical oxidation?

Answer 14

orange —-> green

Question 15

What is the functional group of carboxylic acids?

Answer 15

-COOH

Question 16

Example of an aqueous solution of ethanoic acid

Answer 16

vinegar - when ethanol undergoes microbial oxidation

Question 17

2 observations of metal + carboxylic acid reaction

Answer 17

1. effervescence (H2 produced)
2. solid disappears (metal used up in reaction)

Question 18

example: methanoic acid + sodium —->

Answer 18

sodium methanoate + hydrogen

Question 19

2 observations of metal carbonate + carboxylic acid reaction

Answer 19

1. effervescence (CO2 produced)
2. solid disappears (metal carbonate used up in reaction)

Question 20

example: methanoic acid + sodium carbonate —>

Answer 20

sodium methaonate + water + carbon dioxide

Question 21

What is an ester?

Answer 21

family of organic molecules - forms when a carboxylic acid and alcohol join together, by losing H2O molecule

Question 22

What is the functional group of esters?

Answer 22

-COO-

Question 23

Carboxylic acid + Alcohol —>

Answer 23

ester + water

Question 24

4 steps to make an ester

Answer 24

1. mix alcohol and carboxylic acid together
2. add conc. sulfuric acid (CATALYST)
3. warm it
4. tip mix into sodium carbonate solution (neutralises H2SO4)

Question 25

What is a polyester?

Answer 25

polymer made up of lots of molecules joined together in a chain by ester groups

Question 26

What 2 monomers are need to make a polyester?

Answer 26

1. dicarboxylic acid 2. diol

Question 27

What does it mean that some polyester are biodegradable?

Answer 27

microbes (e.g. bacteria) can use enzymes to break down polymer - reduces landfill and incineration reliance