Organic Chemistry

Question 1

How is crude oil formed?

Answer 1

Dead plants & animals (mainly plankton) were buried under mud and were compressed under high pressure and temperature for millions of years.

Question 2

How is limestone formed?

Answer 2

Calcium carbonate deposits from the shells and skeletons of marine organisms.

Question 3

What is coal made from?

Answer 3

Thick plant deposits.

Question 4

What is crude oil made from?

Answer 4

Deposits of plankton.

Question 5

What is natural gas made from?

Answer 5

Deposits of plankton.

Question 6

Give 5 uses of crude oil hydrocarbons.

Answer 6

Solvents
Detergents
Lubricants
Polymers
Fuels

Pneumonic - smelly dogs like people’s farts

Question 7

As you go up the fractionating column, do the fractions get more or less flammable? Explain why.

Answer 7

More flammable - the shorter chain hydrocarbons have weaker intermolecular forces and so lower boiling points. They are highly volatile.

Question 8

As you go up the fractionating column, do the fractions get more or less volatile?

Answer 8

More volatile

Question 9

Give the general formula for a carboxylic acid.

Answer 9

C_n-1H_2n-1COOH

Question 10

What product(s) are made when sodium reacts with an alcohol?

Answer 10

Hydrogen (+ sodium alkoxide)

You only need to know that hydrogen gas is produced.

Question 11

What happens when you add alcohol to water? Explain your answer.

Answer 11

They dissolve completely to form a neutral solution (ph 7) - they don’t ionise like carboxylic acids do.

Question 12

Alcohol + carboxylic acid -> ?

Answer 12

Ester + water

Question 13

Describe the conditions needed to react ethanol with ethanoic acid.

Answer 13

Strong acid catalyst (e.g. concentrated sulfuric acid)

Question 14

What is needed to hydrogenate an alkene?

Answer 14

A catalyst.

Question 15

What is needed to form an alcohol from an alkene?

Answer 15

A catalyst.

Question 16

What is needed to add halogens to an alkene?

Answer 16

No catalyst.

Haha trick question :)

Question 17

What is needed for the addition polymerisation of alkenes?

Answer 17

High pressure and (sometimes) a catalyst.

Question 18

Give the name of the salt produced when a) methanol, b) ethanol and c) propanol react with a carbonate.

Answer 18

a) methanoate
b) ethanoate
c) propanoate

The salts formed all end in ‘anoate’.

Question 19

What is the structure of a nucleotide?

Answer 19

It contains a phosphate (circle) a sugar (pentagon) and a base (rectangle).

Question 20

Define a polypeptide.

Answer 20

A condensation polymer made of amino acid monomers.

Question 21

Define a protein.

Answer 21

A large molecule containing one or more long chains of polypeptides.

Question 22

What is DNA made of?

Answer 22

Two polymer chains of nucleotide monomers, where each nucleotide contain a small molecule - the base.

Question 23

Explain how different fractions are obtained from crude oil by fractional distillation. [4 marks]

Got 3/4 in Easter holidays.

Answer 23

• crude oil is heated to vaporise (the hydrocarbons)
• there is a temperature gradient in the (fractionating) column
• (so) the gases condense at different levels
• (because of their) different boiling points