Combustion (B): flames, products and cleaner air
Answers are for parents and teachers.
1
Draw a stove flame and say what each colour means.
Blue: complete combustion, more heat. Yellow or orange: incomplete combustion, carbon monoxide and soot.
2
10 g of a gas burn with 40 g of oxygen. The products are 36 g of carbon dioxide and some water. How much water?
10 + 40 = 50 g, so water = 50 − 36 = 14 g.
3
Name two harms of the black cloud and two ways to avoid it.
Harms: poor visibility, worse asthma. Avoid: reuse straw as compost or feed, and avoid burning it in heaps.
4
Explain why a car with a badly kept engine pollutes more.
It burns fuel incompletely, so more carbon monoxide and soot come out.
5
A friend says the converter removes carbon dioxide. Correct this.
It turns CO and nitrogen oxides into CO₂ and N₂; it actually forms carbon dioxide.