Question

solution
3. Write an activity to show:
(a) metals react with oxygen to form
metallic oxides.
(b) nonmetals react with oxygen to form
nonmetallic oxides.
Metals and Nonmetals
53​

Answer 1

Aim :

To show that metal reacts with oxygen to form basic oxides.

Materials Required :

Magnesium ribbon, sand paper, a pair of tongs, Bunsen burner, test tube, water, red litmus paper and blue litmus paper.

Theory:

Metal reacts with oxygen to form basic oxides.

Aqueous solution of metal oxides turns red litmus paper blue (because only basic substances turn red litmus paper blue). Metal Oxygen → Metal oxide [Basic]

Procedure:

(i) Take a small piece of magnesium ribbon and clean its surface with the help of a sand paper.

(ii) Hold the magnesium ribbon at one end with a pair of tongs and bring its other end over the flame of a Bunsen burner till it catches fire.

(iii) Magnesium ribbon burns with a brilliant white light to form a powdery ash of magnesium oxide.

(iv) Take a pinch of white ash in a test tube, add a little water and shake the contents to form a homogeneous solution.

(v) Test the above solution by red and blue litmus papers.

Observation :

The red litmus paper turns blue while there is no change in the colour of blue litmus paper, so magnesium oxide is basic in nature. Reactions Heat 2Mg 2 Mgo Magnesium Magnesium oxide Mgo HO Mg(OH)2 Magnesium oxide Magnesium hydroxide Conclusion Metal oxides (magnesium oxide (MgO)] formed by chemical reaction of metals and oxygen are basic in nature.

Precaution :

Burn the magnesium ribbon carefully in the presence of your teacher.

hope it helps