Year 12 Chemistry Chapter 1

Four identical vehicle models, 1, 2, 3 and 4, were tested for fuel efficiency using LPG, petrol (unleaded, 91 octane), E10 (petrol with 10% ethanol added) and petrodiesel. Carbon dioxide, CO₂, emissions per litre of fuel burnt were also determined. The following table summarises the results. Using the information in the table above, which one of the following statements about petrodiesel is correct?

• It has the highest energy content.

• It has the poorest fuel efficiency.

• It is a renewable energy source.

• It has the lowest CO₂ emissions when burnt.

The use of which vehicle has the smallest impact on the environment, in terms of the grams of CO₂ produced per 100 km?

• Vehicle model 1

• Vehicle model 2

• Vehicle model 3

• Vehicle model 4

A Year 12 Chemistry assignment requires students to quantitatively and qualitatively compare fossil fuels and biofuels.

Which one of the following investigations would be most appropriate for this comparison?

• Use a bomb calorimeter to determine the heat of combustion for both fossil fuels and biofuels.

• Interview car owners to determine what petrol price would make them consider using biofuels.

• Produce biodiesel from vegetable oil and compare the viscosity of the biodiesel produced with that of a range of

  fossil fuels.

• Find reliable information about the environmental impacts of producing fossil fuels and biofuels, and the

  amount of carbon dioxide produced per litre from the combustion of these fuels.

Which one of the following statements about fuels is correct?

• Petroleum gas is a form of renewable energy.

• Electricity can only be generated by burning coal.

• Carbon dioxide is not produced when biogas is burnt.

• Biodiesel can be derived from both plant and animal material.

Coal seam gas is used to generate electricity.

Which one of the following statements applies to coal seam gas?

• Coal seam gas is mostly methane and is found naturally in commercial quantities near some coal deposits.

• Burning coal produces less greenhouse emissions, by mass, than burning coal seam gas.

• Water released during the extraction of coal seam gas is used to irrigate farms.

• Coal seam gas is extracted from decomposing plant and animal material.

Bioethanol, C₂H₅OH, is produced by the fermentation of glucose, C₆H₁₂O₆, according to the following equation.

C₆H₁₂O₆(aq) → 2C₂H₅OH(aq) + 2CO₂(g)

The mass of C₂H₅OH obtained when 5.68 g of carbon dioxide, CO₂, is produced is

• 0.168 g

• 0.337 g

• 2.97 g

• 5.94 g

A student is asked to research and then recommend either petrodiesel or biodiesel as the preferred fuel for a small Victorian transport company. The company stores some of its fuel supplies in tanks situated in remote locations for occasional use. The air temperature in these remote locations can range between 0 °C and 40 °C. Based on this information, the student would recommend petrodiesel rather than biodiesel because petrodiesel is

• more hygroscopic, more viscous and less likely to biodegrade when stored.

• more hygroscopic, less viscous and more likely to biodegrade when stored.

• less hygroscopic, more viscous and more likely to biodegrade when stored.

• less hygroscopic, less viscous and less likely to biodegrade when stored.

Which one of the following lists contains only non-renewable energy sources?

• coal seam gas, petrodiesel, methane gas generated in a digester

• petroleum gas, coal, methane gas in sea-floor sediments

• fossil fuels, biofuels, oil trapped in rock formations

• biogas, bioethanol, diesel composed of methyl esters

Biodiesel

• consists only of hydrogen atoms and carbon atoms.

• produces only carbon monoxide and water when undergoing complete combustion.

• flows very easily when the outside temperature is low.

• absorbs moisture from the air that adversely affects fuel quality.

Which one of the following is a biofuel?

• ethanol produced from crude oil

• ethanol produced from cellulose

• propane produced from natural gas

• electricity produced by hydropower