C3.6 Acids and Alcohols

Question 1

What are alcohols?

Answer 1

A homologous series or organic compounds containing the functional group ending -OH

Question 2

What do you call a family of compounds that have similar properties and functions?

Answer 2

A homologous series

Question 3

What is the basic arrangement for an alcohol?

Answer 3

CH3 CH2 OH = ethanol

As the alcohol molecule grows larger, more CH2s are added

eg
H H
H- C - C - O - H
H H

Question 4

How are alcohols named?

Answer 4

Meth   = 1 Carbon
Eth     = 2 Carbons
Prop    =3 Carbons
But    = 4 Carbons
Pent    = 5 Carbons

+ Anol / ol

Question 5

What are the properties of methanol, ethanol and propanol?

Answer 5

• Highly flammable
• Colourless liquids
• Dissolve in water to form a neutral solution
• Reactions with sodium produce HYDROGEN + SALT
• Burn / react with air to produce carbon dioxide + water

Question 6

What are carboxylic acids?

Answer 6

A homologous series with the same functional group

-COOH

Question 7

How are carboxylic acids named?

Answer 7

Meth,Eth,Prop,But,Pent

+ anoic acid

eg METHanoic acid

Question 8

How are carboxylic acids arranged?

Answer 8

HCOOH / CH3COOH / CH3CH2COOH

eg
H O
H - C - C
H O - H

The top O has a double bond

Question 9

How can ethanoic acid be formed from ethanol?

Answer 9

Ethanoic acid can be formed due to mild oxidation

such as slight fermentation by the action of microbes in aerobic conditions
or
Addition of chemical oxidation agents such as acidified potassium dichromate

Question 10

What are the properties of Carboxylic acids?

Answer 10

• Dissolve in water to produce ACIDIC solutions
• React with carbonates to produce CARBON DIOXIDE + SALT + WATER
• React with alcohols ( + catalyst ) to form esters
  eg ethanol + ethanoic acid → ethyl ethanoate + water

Question 11

What makes carboxylic acids weak acids?

Answer 11

They do not completely ionise in water, they only lose SOME H+ ions

An acid is judged on its ability to lose ions