Year 9 Science · Unit 2 · Lesson 15

Hydrocarbon Products and Energy Transition

Foundation Worksheet

Name

Date

Class

Learning Goals

Sort crude oil products into fuels and feedstocks.
Write a balanced equation for cracking by counting carbon and hydrogen atoms.
Use supply and demand data to explain why refineries crack heavy fractions.

Warm Up

True or false? Fix the false ones

Circle T or F. If a statement is false, correct it on the line.

Crude oil is used only as a fuel.

Correct it:

Switching electricity generation to renewables is easier than replacing the crude oil used to make plastics and chemicals.

Correct it:

Catalytic cracking uses a zeolite catalyst to break long hydrocarbon chains at lower temperatures than thermal cracking.

Correct it:

Cracking produces only alkanes; no alkenes are formed.

Correct it:

Ethene made by cracking can be turned into the plastic polyethylene.

Correct it:

1. Define the energy transition in one sentence. Then name two renewable sources of electricity.

Recall 2 marks

Your Turn

Sort it: fuel or feedstock?

Burned for energy, or built into something new? Write each use in the correct box.

petrol in a car ethene made into polyethylene LPG in a barbecue jet fuel in a plane petrochemicals made into medicines propene made into food containers diesel in a train petrochemicals made into fertilisers

Fuel

Feedstock

2. Dodecane, C₁₂H₂₆, is cracked into octane, C₈H₁₈, and one other molecule. Atoms are not created or destroyed, so the other molecule gets every atom that octane does not. Complete the table.

Apply 2 marks

Atom	C₁₂H₂₆ minus C₈H₁₈	Left for the other molecule
C	12 − 8
H	26 − 18

3. Name the missing molecule by its formula, then write the full equation for this reaction. It has one C=C double bond: which family does that put it in?

Apply 3 marks

Go Deeper

Scenario: a refinery with the wrong mix

Distilling crude oil gives fixed amounts of each fraction. Those amounts do not match what customers buy.

Table 1. What one refinery’s crude oil gives, and what its customers want

Fraction	Made by distillation (%)	Wanted by customers (%)
LPG	4	4
Petrol	20	40
Kerosene	13	10
Diesel	23	38
Heavy fuel oil and bitumen	40	8

Source: simplified figures for practice, built around the lesson’s approximate values (about 20% of a crude is petrol-range, while petrol is about 40% of demand).

4. Which two fractions are most in short supply? Which fraction has the biggest surplus?

Apply 2 marks

5. Calculate the total shortage of petrol and diesel together, and the surplus of heavy fuel oil and bitumen, in percentage points.

Analyse 2 marks

Shortage points

Surplus points

6. Use your answers to explain how cracking can fix both problems at once.

Analyse 2 marks

Show What You Know

7. Cracking uses a lot of energy, yet every major refinery does it. Explain why cracking is worth doing for the refinery in Table 1. Use the data and your cracking equation.

Apply 4 marks