Alcohols

Question 1

Why do alcohols have higher boiling point than a alkane ?

Answer 1

Because of the hydrogen bonding in alcohols

Question 2

What does the electronegative Oxygen in the hydroxyl group make the alcohol?
And what type of bonding can happen w this hydroxyl group?

Answer 2

POLAR , HYDROGEN BONDING

Question 3

What does volatility mean

Answer 3

Easy to evaporate , gets hot quick

Question 4

What term is used when liquids are soluble in other liquids ?

Answer 4

Miscibility

Question 5

Why are alcohols soluble in water?

Answer 5

They can form hydrogen bonds with water molecules

Question 6

What happens to solubility as size of alcohol increases and why

Answer 6

Solubility Decreases as hydrocarbon chain increases in size

Question 7

What are the 5 reactions of alcohols ?

Answer 7

Combustion
Dehydration
Substitution
Esterification
Oxidation

Question 8

IN COMUBSTION alcohols react w excess oxygen to form what?

Answer 8

Carbon dioxide + water

Question 9

Write full equation for complete combustion of ethanol

Answer 9

C2H6O + 3O2 —> 2CO2 + 3 H2O

Balance the C first then H then O

Question 10

DEHYDRATION means to remove what from a molecule ?

Answer 10

WATER

Question 11

Alcohols are dehydrated using what as a dehydrating agent?

Answer 11

H2SO4 or concentrated H3PO4

Question 12

Wha are the conditions for dehydration of alcohols

Answer 12

REFLUX

Question 13

What is formed as a product of dehydration of ALCOHOLS

Answer 13

An Alkene

Question 14

what is the mechanism called for dehydration of Alcohols

Answer 14

ELIMINATION (don’t need to draw mechanism )

Question 15

What do alcohols form when they react w hydrogen halides ( substitution )

Answer 15

HALOALKANE

Question 16

In esterification Alcohols react with ___ in the presence of ____ to form _____+_____ WHAT IS THIS CALLED?

Answer 16

Carboxylic acid , concentrated sulfuric acid, esters +water
CONDENSATION REACTION - 2 molecules add together with elimination of water

Question 17

Esterification of alcohols

Answer 17

Question 18

What is the reagent In OXIDATION of alcohols ?

Answer 18

Acidified potassium dichromate

Question 19

What does acidified potassium dichromate act as

Answer 19

OXIDISING AGENT

Question 20

what colour change is observed when alcohol is oxidised by oxidising agent?

Answer 20

Orange to Green

Question 21

What new bond is formed when oxidation occurs

Answer 21

CARBONYL C=O

Question 22

WHAT REAGENT IS ALWAYS used when oxidising alcohols

Answer 22

Acidified potassium dichromate

Question 23

What are the conditions for when a primary alcohol is oxidised into a aldehyde

Answer 23

DISTILLATION
EG

Question 24

What conditions are required for when a Aldehyde is oxidised to a carboxylic acid

Answer 24

REFLUX + excess acidified potassium dichromate
Eg

Question 25

Write the overall equation for when a primary alcohol is oxidised to form carboxylic acid ETHANOL TO ETHANOIC ACID

Answer 25

Question 26

What are SECONDARY alcohols oxidised to?

Answer 26

KETONES

Question 27

what are the conditions and reagents for secondary alcohol to ketone

Answer 27

REAGENT - acidified potassium dichromate CONDITION- distillation

Question 28

WHAT is ALWAYS produced during oxidation of alcohols ?

Answer 28

WATER

Question 29

Propan-2-ol oxidised to propanone

Answer 29

Question 30

Can tertiary alcohols be oxidised ?

Answer 30

NO

Question 31

why can’t ketones not be oxidised further easily

Answer 31

C-C bond is too strong

Question 32

What is distillation used for

Answer 32

To separate a mixture of liquids with different boiling points

Question 33

WHICH molecule has highest boiling point and lowest boiling point and why ETHANOL ETHANAL ETHANOIC ACID

Answer 33

ethanal

Question 34

what does REFLUX mean

Answer 34

Vapour condenses and drips back into the reaction flask. Prevents the loss of reactant vapour

Question 35

WHEN IS REFLUX REQUIRED

Answer 35

When oxidising primary alcohol to carboxylic acid

Question 36

Draw the reflux diagram

Answer 36