3.3.5- Alcohols

Question 1

What reagent is needed for hydration

Answer 1

Alkene

Question 2

What condition are needed for hydration

Answer 2

Catalyst -phosphoric acid/ sulphuric acid
High temperature
High pressure

Question 3

Equation of Ethene in a hydration reaction

Answer 3

C2H4 +H2O – C2H5OH

Question 4

Advantages of hydration

Answer 4

Fast reaction
Pure product
Continuous process

Question 5

Disadvantages of hydration

Answer 5

Non renewable resources

Expensive equipment

Question 6

Uses of alcohols

Answer 6

Alcoholic drink
Solvents
Fuel (petrol substitute)

Question 7

What reagent is needed in fermentation

Answer 7

Glucose from hydrolysis of starch

Question 8

Conditions for fermentation

Answer 8

Yeast

Warm but no higher than 37

Question 9

Equation for fermentation of glucose

Answer 9

C6H12O6 — 2C2H5OH +2CO2

Question 10

Advantages of fermentation

Answer 10

Low energy process
Renewable resource
Simple equipment

Question 11

Disadvantages of fermentation

Answer 11

Slow
Produced impure ethanol
Batch process

Question 12

What is used after fermentation

Answer 12

Fractional distillation separate so can be used as biofuel

Question 13

Define biofuel

Answer 13

A fuel derived immediately from living matter

Question 14

What are primary alcohols oxidised to

Answer 14

Aldehyde then to carboxylic acids

Question 15

What are 2 methods of oxidising alcohols

Answer 15

Distillation

Refluxing

Question 16

What does distillation produce and equation

Answer 16

Gives an aldehyde

CH3CH2OH + [O] -> CH3CHO +H2O

Question 17

What does refluxing produce and an equation

Answer 17

Gives a carboxylic acid
CH3CH2OH+ [O] – CH3CHO + H2O

CH3CHO+ [O] – CH3COOH

Question 18

What do secondary alcohols oxidise to

Answer 18

Ketones

Question 19

Equation for oxidation of prop-2-ol

Answer 19

CH3CHOHCH3 + [O] – CH3COCH3 +H2O

Question 20

What do tertiary alcohols oxidise to

Answer 20

They do not easily oxidise

Question 21

What reagents are used in oxidation

Answer 21

Acidified potassium dichromate (VI) 
Potassium maganate (VII)

Question 22

Test for an alcohol

Answer 22

K2Cr2O7

Goes orange to green with primary and secondary alcohols

Question 23

3 tests for aldehydes

Answer 23

Tollens
Fehlings
Acidified K2Cr2O7

Question 24

Explain tollens reagent test

Answer 24

Colourless to silver mirror with aldehyde

Question 25

Explain fehlings solution test

Answer 25

Add fehlings a and b and then a blue to red with an aldehyde

Question 26

Explain acidified potassium dichromate test

Answer 26

Orange to green with aldehyde

Question 27

2 tests for carboxylic acids

Answer 27

NaHCO3/Na2CO3

Litmus paper

Question 28

Explain NaHCO3/Na2CO3

Answer 28

Produce effervescence with carboxylic acid

Question 29

Explain litmus paper test

Answer 29

Test solution should turn red from blue

Question 30

2 ways elimination can occur

Answer 30

Conc H2SO4
Reflux 180
Or
Pass vapour over heated aluminium oxide catalyst

Question 31

Show equation for elimination

Answer 31

C2H5OH –CH2=CH2 + H2O

Question 32

Draw equation of reflux elimination

Answer 32

Draw

Question 33

Draw equation of heated catalyst elimination

Answer 33

Draw