Class 8 Science – Chapter 4
Materials: Metals and Non-Metals
Page 4: Reactions with Acids & Displacement

---

1️⃣ Reaction of Metals with Acids

Most metals react with dilute acids to produce salt and hydrogen gas.

Example:

Zinc + Dilute Hydrochloric Acid → Zinc Chloride + Hydrogen

The hydrogen gas produced burns with a ‘pop’ sound.

2️⃣ Reaction of Non-Metals with Acids

Non-metals do not react with dilute acids and hence do not produce hydrogen gas.

3️⃣ Reaction of Metals with Bases

Some metals like zinc and aluminium react with strong bases such as sodium hydroxide.

Example:

Zinc + Sodium Hydroxide → Sodium Zincate + Hydrogen

4️⃣ Displacement Reactions

A more reactive metal can displace a less reactive metal from its compound.

Example:

Iron + Copper Sulphate → Iron Sulphate + Copper

In this reaction, iron displaces copper because iron is more reactive.

⭐ Exam Tip: Displacement reactions depend on the reactivity series of metals.