Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Inorganic Chemistry
869 practice questions
Topics covered
- The Alkali Metals85 practice questions
- The Halogens86 practice questions
- Gases in the Atmosphere86 practice questions
- Reactivity Series163 practice questions
- Extraction and Uses of Metals128 practice questions
- Acids, Alkalis and Titrations83 practice questions
- Acids, Bases and Salt Preparations156 practice questions
- Chemical Tests68 practice questions
Practice questions
161–170 of 374 · Normal
Question 161
2 marks · Normal
Answer and see the solution →State why rusting is more rapid in salty water than in pure water.
Question 162
4 marks · Normal
Answer and see the solution →A bicycle frame made from iron is left outside in the rain.
(a)[1 mark]State the two conditions required for rusting of iron to occur.
(b)[1 mark]Describe how painting the bicycle frame prevents rusting.
(c)[2 marks]Explain why coating the frame with zinc protects the iron even if the paint or zinc layer is scratched, using the idea of the reactivity series.
Question 163
2 marks · Normal
Answer and see the solution →State the two conditions necessary for iron to rust. Describe briefly how galvanising prevents rusting.
Question 164
4 marks · Normal
Answer and see the solution →A farmer is installing a new iron gate that will be exposed to rain and air.
(a)[1 mark]Explain why the gate will rust if left unprotected.
(b)[2 marks]Describe two ways, other than galvanising, that could prevent the gate from rusting.
(c)[1 mark]State and explain why galvanising remains effective even if the zinc coating is scratched.
Question 165
3 marks · Normal
Answer and see the solution →A section of iron gutter is to be protected from rusting by galvanising. The gutter is 2.5 m long and each square metre of iron requires 80 g of zinc for an even, protective coating.
(a)[1 mark]State the two conditions required for rusting of iron to occur.
(b)[2 marks]The gutter has a surface area of 0.30 m². Calculate the minimum mass of zinc needed to galvanise the entire surface. Show your working and give your answer in grams.
Question 166
2 marks · Normal
Answer and see the solution →Describe how sacrificial protection prevents iron from rusting.
Question 167
4 marks · Normal
Answer and see the solution →The diagram shows an iron pipeline buried underground with blocks of magnesium attached at intervals.
(a)[2 marks]Explain why the magnesium blocks must be more reactive than iron in order to protect the pipeline from rusting.
(b)[2 marks]Explain what happens to the magnesium during this process.
Question 168
3 marks · Normal
Answer and see the solution →A ship’s iron hull is protected from rusting by sacrificial anodes. Each anode is made from magnesium and has a mass of 6 kg. Over a year, each anode loses 1.5 kg of magnesium.
(a)[1 mark]State one structure, apart from a ship, that is protected by sacrificial anodes.
(b)[2 marks]Calculate the percentage of magnesium lost from each anode in a year.
Question 169
3 marks · Normal
Answer and see the solution →Rusting occurs when iron is exposed to air and water. Ships are often fitted with blocks of zinc on their hulls.
(a)[3 marks]Explain, using the ideas of oxidation and reactivity, how these zinc blocks prevent the iron hull from rusting.
Question 170
4 marks · Normal
Answer and see the solution →A scientist is choosing a metal to protect an iron water tank from rusting. She tests three metals (A, B, and C), each attached to iron and left in moist air. The results are shown below.
Results: Rusting of iron with different metals attached Metal attached Observation after 1 month A Iron is rusted; attached metal is not corroded B Iron is shiny; attached metal is heavily corroded C Iron is rusted; attached metal is also rusted (a)[2 marks]Which metal, A, B, or C, acts as a sacrificial anode for iron? Explain your answer.
(b)[2 marks]Explain, using the observations, why the chosen metal must be more reactive than iron.