1. A fuel undergoes combustion to heat water. Which of the following descriptions of the energy and enthalpy of combustion, ∆H, of the reaction is correct?

Solution

2. Researchers have identified pathways that will enable production of the biofuel
2-methylpropan-1-ol from proteins. 2-methylpropan-1-ol can be used in petrol engines. 2-methylpropan-1-ol has a heat of combustion of 36.1 kJ g^-1.

a. Compare the energy content of octane and
2-methylpropan-1-ol. Explain the difference. 2 marks

Solution

b. A small fuel burner containing 2.36 g of 2-methylpropan-1-ol was placed directly underneath a beaker containing 500.0 g of water at standard laboratory conditions (SLC). Calculate the maximum temperature that the water could reach if the contents of the fuel burner underwent complete combustion. 3 marks

Solution

3. Consider the following statements regarding biodiesel and petrodiesel:
I Petrodiesel is more hygroscopic than biodiesel.
II Biodiesel forms crystals at a higher temperature than petrodiesel.
III Biodiesel and petrodiesel are derived from plants and animals.
IV The combustion of biodiesel releases less sulfur dioxide than petrodiesel.

Which of the statements above are correct?
A. I and IV only
B. III and IV only
C. I, II and III only
D. II, III and IV only

Solution