CHEMISTRY C1 4

Question	Answer
What is in crude oil?	A mixture of many different compounds
What are alkanes?	Saturated hydrocarbons with the highest amount of hydrogen atoms as possible in their molecules
What is the general formula for alkanes?	C(n)H(2n+2)
How do we separate crude oil into fractions?	Using fractional distillation
What are the stages of fractional distillation?	Image: fractional_di (image/jpg)
What makes a fraction useful as a fuel?	Lighter fractions are more useful as fuels because they ignite easier and burn well with cleaner (less smoky) flames
What are the products of combustion when we burn fuels in a good supply of air?	The hydrogen and carbon in the fuel are completely oxidised and produce water and carbon dioxide
What happens if there are sulfur impurities in fuels?	They burn to form sulfur dioxide which can cause acid rain
What happens if we burn a fuel with insufficient oxygen?	We get poisonous carbon monoxide as well as particles of carbon(soot) and unburnt hydrocarbons
What happens when nitrogen reacts with oxygen at high temperatures in engines?	Nitrogen oxides are formed, these can cause breathing problems and acid rain.
Why is carbon dioxide called a greenhouse gas?	It absorbs energy which is lost by radiation from the surface of the Earth
What are biofuels?	A renewable source of energy that could be used to replace some fossil fuels
What can biodiesel be made from?	vegetable oils
Why is Ethanol a biofuel?	It can be made from sugar in plants
Name a potential fuel for the future	Hydrogen

Resource summary

	Created by x_clairey_x over 10 years ago