1) Which one of the following statements is correct?
A. Crude oil can be classified as a biofuel because it originally comes from plants.
B. Methane, CH₄, can be classified as a fossil fuel because it has major environmental impacts.
C. Ethanol, CH₃CH₂OH, can be classified as a fossil fuel because it can be produced from crude oil.
D. Hydrogen, H₂, can be classified as a biofuel because, when it combusts, it does not produce carbon dioxide, CO₂.
Solution

2) Petrodiesel is made up of a number of different molecules, including C₁₂H₂₆. Biodiesel often contains C₁₁H₂₂O₂. When comparing C₁₂H₂₆ and C₁₁H₂₂O₂, which one of the following statements is correct?
A. C₁₂H₂₆ has a higher viscosity due to the dispersion forces between the molecules.
B. C₁₂H₂₆ is less hygroscopic as it has only dispersion forces between the molecules.
C. C₁₁H₂₂O₂ has a higher energy content when it combusts as it contains oxygen atoms.
D. C₁₁H₂₂O₂ produces more carbon dioxide per mole when it combusts due to its higher molecular weight.

Solution

3) The combustion of which fuel provides the most energy per 100 g?
A. pentane (M = 72 g mol⁻¹), which releases 49097 MJ tonne⁻¹
B. nitromethane (M = 61 g mol⁻¹), which releases 11.63 kJ g⁻¹
C. butanol (M = 74 g mol⁻¹), which releases 2670 kJ mol⁻¹
D. ethyne (M = 26 g mol⁻¹), which releases 1300 kJ mol⁻¹

Solution