Gasoline (petrol)
3 marks · NormalMost cars use gasoline (petrol) as a fuel.
Explain why gasoline, rather than refinery gases, is usually chosen as the preferred fuel for cars.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
Gasoline is liquid at room temperature, making it easy to store and transport in vehicles; it is more energy-dense; it burns smoothly and safely in internal combustion engines, whereas refinery gases are difficult to store and may require heavy pressurised tanks.
Also accept: Gasoline is easier to store and use in vehicles than gases, which require special tanks or cylinders; Gasoline burns efficiently and is safer for cars compared to refinery gases
Common mistakes: simply stating 'because cars use petrol' without explanation; confusing physical state of fuels
Show mark scheme and worked solution
Marking points
B1 · 1 mark · States gasoline is liquid at room temperature and easy to store/transport in cars.
B2 · 1 mark · Explains gasoline has high energy density or burns smoothly in engines.
B3 · 1 mark · Mentions refinery gases are difficult to store (require pressurised tanks) or are unsafe.
Worked solution
Gasoline is liquid at room temperature, making it easy to store and dispense in cars. It has a high energy content and burns efficiently in car engines. Refinery gases are gaseous at room conditions and need pressurised tanks, making them less convenient and less safe for most cars.