Basic Organic Chemistry

Question 1

What is crude oil?

Answer 1

Formed from ancient plankton buried under mud, high pressure, and heat over millions of years. A finite resource. A mixture of hydrocarbons.

Question 2

What are hydrocarbons made of?

Answer 2

Carbon + hydrogen only.

Question 3

What are the two types of hydrocarbons?

Answer 3

• Alkanes: Single bonds, saturated – CₙH₂ₙ₊₂ (e.g., methane CH₄)
• Alkenes: Double bond, unsaturated – CₙH₂ₙ (e.g., ethene C₂H₄)

Question 4

What test can be used to identify alkenes?

Answer 4

Turns bromine water from orange → colourless.

Question 5

Describe the process of fractional distillation of crude oil.

Answer 5

Crude oil is heated until vaporised. Vapours rise in a fractionating column. Different hydrocarbons condense at different heights (based on boiling points).

Question 6

List the fractions obtained from fractional distillation of crude oil and their uses.

Answer 6

• LPG: Cooking gas
• Petrol: Car fuel
• Kerosene: Jet fuel
• Diesel: Lorry fuel
• Fuel oil: Ship fuel
• Bitumen: Road surfacing

Question 7

What are the properties of LPG?

Answer 7

Very flammable, low BP.

Question 8

What are the properties of petrol?

Answer 8

Volatile, burns clean.

Question 9

What is the use of kerosene?

Answer 9

Jet fuel.

Question 10

What are the properties of diesel?

Answer 10

Less volatile.

Question 11

What is the use of fuel oil?

Answer 11

Ship fuel.

Question 12

What are the properties of bitumen?

Answer 12

Very viscous, solid at RT.

Question 13

What is the equation for complete combustion of hydrocarbons?

Answer 13

Hydrocarbon + O₂ → CO₂ + H₂O.

Question 14

What happens during incomplete combustion?

Answer 14

Produces CO (carbon monoxide), C (soot), and less energy.

Question 15

True or False: Carbon monoxide is non-toxic.

Answer 15

False.

Question 16

What is the effect of carbon monoxide on the body?

Answer 16

Prevents oxygen transport in blood.