Question

Thin strips of magnesium, copper, and iron are taken.

Write down what happens when these metals are treated as follows:

1. Heated in presence of air
2. Heated with dil.HCl
3. Added to an aqueous solution of zinc sulphate.

Answer 1

1. On heating thin strips of magnesium, copper, and iron, they form oxides.
2. Magnesium and iron react with HCl liberating hydrogen and forming their respective salts. Hydrogen cannot be prepared from metals that are below it in the activity series of metals (such as copper) because only metals that are more reactive than hydrogen can displace it from acids.
3. Only magnesium will displace zinc from zinc sulphate solution because magnesium is more reactive than zinc in the activity series of metals. No reaction takes place in the case of copper and iron because they are less reactive than zinc.