NCERT Activity 3.8 Class 10 Science Explanation

In this activity, we will discuss the nature of oxides of metals and non-metals.

Aim of the activity

To compare the nature of oxides formed by metals and non-metals

Materials Required

    1. Magnesium ribbon

    2. Sulphur powder

    3.  Test tubes

    4. Water

    5.  Red and blue litmus paper

    6. Spirit lamp

    7. Tongs

Procedure

 We will perform this activity in the following steps:

(1)      Burning of Magnesium Ribbon

(2)      Burning of Sulphur Powder

(1)      Burning of Magnesium Ribbon

We take a magnesium ribbon and burn it using tongs. We collect white ash in the test tube and dissolve it in water. Now we dip red and blue litmus paper in it and observe the colour change.

(2)      Burning of Sulphur Powder

 We take a small amount of sulphur powder in a spoon and burn it. We cover the burning sulphur with a test tube to collect fumes. Now we add some water to the test tube and dip the red and blue litmus papers. We observe the colour change.

 

Observation

   1.  Magnesium oxide solution turns red litmus paper blue.

    2. Sulphur dioxide solution turns blue litmus red.

Explanation

Magnesium ( a metal )reacts with oxygen (air) to form a basic oxide

 

   2Mg + O₂  →2MgO

When water is added to magnesium oxide, it forms magnesium hydroxide, a base which turns red litmus blue.

  MgO(s) +  H₂O(l)  →  Mg(OH)₂(aq)

 

 

 Sulphur (non-metal) reacts with oxygen to form sulphur dioxide.

  S+ O₂ →  SO₂

When water is added to sulphur dioxide, it forms sulphurous acid, which turns blue litmus red.

 SO₂(g) + H₂O(I) → H₂SO₃(aq)

Conclusion

This activity demonstrates that metal oxide is basic in nature, and the oxide of a non-metal is acidic in nature.

Frequently Asked Questions

    1.  What is the colour of magnesium oxide?

Answer - White

    2. Which gas is evolved when sulphur is burnt in air?

Answer – Sulphur dioxide gas, a pungent-smelling gas

  3. Name the product formed when water is added to magnesium oxide.

Answer – Magnesium hydroxide

   4. What is the formula of magnesium hydroxide?

Answer – Mg(OH)₂