Corrosion of metals

The diagram illustrates how an iron pipe beneath water can be protected from rusting. Metal $Z$ can be ...... because it is ..... reactive than iron. Which words correctly fill gaps 1 and 2?

May/June 2015

Two separate pieces of iron are shown in water, with zinc attached to one and copper attached to the other, as illustrated. Which of the following statements are correct?

May/June 2015

Which element, when connected to iron placed in salt water, would stop the iron from corroding?

May/June 2016

Following the failure of a river bridge, a new car was submerged in the river water for several months. After it was retrieved, the car parts made from steel, an alloy of iron, were found to have corroded. The parts made of aluminium had not corroded. Which statement accounts for these differences in corrosion?

May/June 2017

Which metal is used to galvanise iron?

May/June 2018

Fixing pieces of magnesium onto iron pipes buried underground can prevent the iron from corroding. Which reaction is responsible for protecting the iron from corrosion?

May/June 2021

By fastening pieces of magnesium to iron pipes buried underground, the iron can be protected against corrosion. Which reaction provides this protection?

May/June 2021

Zinc is used to galvanise iron, which stops the iron from rusting. Which of these statements are correct? 1 The zinc layer acts as a barrier separating the iron from oxygen and water in the air. 2 Zinc oxidises before the iron does, even if the zinc layer is scratched. 3 When iron rusts, iron atoms gain electrons and form ions.

May/June 2023

Small pieces of magnesium may be fixed onto the steel hull of a ship in order to stop rust from forming. This is known as sacrificial protection. Which of the following statements about sacrificial protection are correct?

May/June 2023

A student is investigating rusting in iron. Fig. 1.1 displays the apparatus used by the student.

May/June 2023

Iron is galvanised with zinc to stop rusting. What type of protection does galvanising provide?

May/June 2025

Which statement gives the reason that objects made from aluminium corrode very slowly?

May/June 2025

Aluminium is used to make aircraft and food containers. It resists corrosion when exposed to water and oxygen.

May/June 2025

Fixing pieces of magnesium onto iron pipes that are buried underground can prevent the iron from corroding. Which reaction is responsible for protecting the iron from corrosion?

Oct/Nov 2016

Which metal is fixed to underground iron pipes to give sacrificial protection against corrosion?

Oct/Nov 2017

Aluminium is a metal that is commonly used to produce bottle caps. If these caps are discarded and placed in soil, they do not corrode. What is the reason for this?

Oct/Nov 2017

Aluminium is used to make saucepans because it appears to be unreactive. Which property of aluminium accounts for this lack of reactivity?

Oct/Nov 2018

Aluminium is used to make saucepans because it seems to be relatively unreactive. Which property of aluminium accounts for this unreactivity?

Oct/Nov 2018

Steel is frequently galvanised. Which of the following statements about galvanising are correct?

Oct/Nov 2021

Which statements concerning the corrosion of iron are correct?

Oct/Nov 2021

The majority of metals react with oxygen in the air to produce a metal oxide. Which metal produces a metal oxide coating that lowers its apparent reactivity?

Oct/Nov 2023

Which statement concerning corrosion of metals is correct?

Oct/Nov 2023

Iron rusting may be stopped by covering the iron with a different material. Which statement shows why a zinc coating is more effective than a painted coating?

Oct/Nov 2023

The diagrams illustrate two ways in which metal X is applied to stop iron from rusting. A student claims that metal X must be less reactive than iron and must have a smaller proton number than iron. Which of these claims are correct?

Oct/Nov 2025

A piece of zinc is fixed to a steel car to stop it rusting. Which statement is correct?

Oct/Nov 2025