Exam-style questions 1
The diagram shows a water treatment works. aluminium sulfate added water in chlorine added sedimentation tank
to homes sand filter
a b c d
State one use of water in industry. Explain how the sand filter helps purify the water. The aluminium ions in aluminium sulfate cause clay particles to clump together. Describe a test for aluminium ions. Why is chlorine added to the water?
[1] [2] [3] [1]
CIE IGCSE, June 2008, paper 2, q.4 part
2
The diagram shows a statue in a park in an industrial town. The statue is made from limestone.
iron pins inside statue
statue when first erected
a b c
the same statue after 20 years
State the name of the chemical present in limestone. Use ideas about the chemistry of atmospheric pollutants to suggest how and why the statue changes over 20 years. Parts of the statue are joined together with iron pins. After 30 years, the arm falls off the statue. Suggest why the arm falls off.
[1] [4] [1]
CIE IGCSE, June 2008, paper 2, q.2 part
Chapter 1
Planet Earth
21