Combustion and fuelsIB MYP Chemistry: Mind map

Exam questions on Combustion and fuels

1. A family in Istanbul cooks on a gas hob that burns methane (natural gas). The flame is normally blue. One evening the flame turns yellow and black soot appears on the bottom of the pans. An engineer finds that the air holes of the burner are blocked.
   Explain why the flame turned yellow and left black soot on the pans.2 marks
2. A student in Lagos investigates the products made when ethanol burns in a spirit burner. She uses a pump to draw the waste gases through a U-tube surrounded by ice, and then bubbles the remaining gas through limewater. A colourless liquid collects in the U-tube and the limewater turns cloudy.
   Write the word equation for the complete combustion of ethanol.2 marks
3. Crude oil and natural gas are fossil fuels. They are found under the seabed in countries such as Norway and are burned in power stations, vehicles and homes.
   Describe how crude oil and natural gas were formed.3 marks