Four different metals are separately mixed with an equal volume of dilute hydrochloric acid. The table shows the rate of effervescence for each metal. What is the order of reactivity of the four metals starting with the most reactive?

iron \(\rightarrow\) magnesium \(\rightarrow\) calcium \(\rightarrow\) copper

magnesium \(\rightarrow\) calcium \(\rightarrow\) copper \(\rightarrow\) iron

copper \(\rightarrow\) iron \(\rightarrow\) magnesium \(\rightarrow\) calcium

calcium \(\rightarrow\) magnesium \(\rightarrow\) iron \(\rightarrow\) copper

Chemistry

IGCSE&ALevel

CAIE

Exam No：0620_s24_qp_13 Year：2024 Question No：28

Answer:

9.5.1. State the conditions required for the rusting of iron and steel to form hydrated iron(III) oxide

9.5.2. State some common barrier methods, including painting, greasing and coating with plastic

9.5.3. Describe how barrier methods prevent rusting by excluding oxygen or water

9.5.4. Describe the use of zinc in galvanising as an example of a barrier method and sacrificial protection

9.5.5. Explain sacrificial protection in terms of the reactivity series and in terms of electron loss