C3 Organic Chemistry

Question 1

What links the three organic compounds, alcohols, carboxylic acids and esters?

Answer 1

Alcohols react with carboxylic acids to produce esters.

Question 2

What does the word organic mean here?

Answer 2

The compound is based on the element carbon. It may contain hydrogen too.

Question 3

What is a functional group?

Answer 3

The reactive bit of an organic compound.

Question 4

What is an homologous series?

Answer 4

The compounds with the same functional group are arranged in order of carbon chain length.

Question 5

What is the molecular formula of ethanol?

Answer 5

C₂H₆O

Question 6

What is the structural formula of ethanol?

Answer 6

CH₃CH₂OH

Question 7

What is the displayed formula of ethanol?

Answer 7

Question 8

Name the first three members of the alcohol homologous series? How do their names give them away?

Answer 8

Methanol, ethanol and propanol, their names all end in -ol

Question 9

What is the functional group in an alcohol?

Answer 9

Alcohols contain the functional group –OH

Question 10

What are the chemical properties of alcohols?

Answer 10

They dissolve in water to form a neutral solution; they react with sodium to produce hydrogen; they burn in air.

Question 11

Write an equation for the combustion of ethanol.

Answer 11

Ethanol + oxygen → carbon dioxide + water

C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O

Question 12

What are the uses of alcohols generally?

Answer 12

They are used as fuels and solvents.

Question 13

Give two specific food related uses of ethanol.

Answer 13

Ethanol is the main alcohol in alcoholic drinks. Ethanol can be oxidised to ethanoic acid, either by chemical oxidising agents or by microbial action. Ethanoic acid is the main acid in vinegar.

Question 14

Name the first three members of the carboxylic acid homologous series? How do their names give them away?

Answer 14

Methanoic acid, ethanoic acid and propanoic acid They all end in –oic acid.

Question 15

What’s the functional group in a carboxylic acid?

Answer 15

They have the functional group –COOH

Question 16

What are the acidic properties of alcohols?

Answer 16

They dissolve in water to produce acidic solutions. They react with carbonates to produce carbon dioxide

Question 17

Why are they weak acids?

Answer 17

They do not ionise completely when dissolved in water and so are weak acids

Question 18

What are the uses of carboxylic acids generally?

Answer 18

They react with alcohols in the presence of an acid catalyst to produce esters

Question 19

What are the uses of carboxylic acids generally?

Answer 19

They react with alcohols in the presence of an acid catalyst to produce esters

Question 20

Give a food related use of ethanoic acid?

Answer 20

Ethanoic acid is the main acid in vinegar

Question 21

What is the functional group in an ester?

Answer 21

Esters have the functional group –COO–.

Question 22

What are the physical properties of esters?

Answer 22

They are volatile compounds with distinctive smells

Question 23

What are the uses of esters?

Answer 23

They are used as flavourings and perfumes.

Question 24

What is ethyl ethanoate?

Answer 24

Ethyl ethanoate is the ester produced from ethanol and ethanoic acid.