Exam Questions

Question 1

It is easier to produce bioethanol from sugar cane than from forest waste. Discuss why researchers might still be interested in the forest waste project.

Studyclix

(2 Marks)

Answer 1

• The primary use of sugar cane is to produce sugar and Australia does not have significant capacity to expand its production for fuel (1)
• Forest waste is genuine waste material – any use for it is a gain (1)

Question 2

Describe and explain the difference in viscosity, under the same conditions, of petrodiesel and biodiesel and how this would affect the flow of each fuel.

VCAA 2017, Question 2a

(3 Marks)

Answer 2

• Biodiesel has a higher viscosity (flows less easily) than petrodiesel
• This is bc of stronger intermolecular attraction between biodiesel molecules than petrodiesel molecules due to:
• Stronger dispersion forces bc of longer molecules/carbon chain
• Dipole-dipole attraction bc of presence of ester