Activity 4.6 Class 8 Science Chapter 4

 Activity 4.6 Class 8 Science Chapter 4 Materials: Metals and Non-metals

In this post, you will find NCERT Science Class 8 Chapter 4 Materials: Metals and Non-metals Activity solutions.  Class 8 science chapter 4 consists of NCERT Activity 4.6 Class 8 Science Explanation with a conclusion.

NCERT Activity 4.6 Class 8 Science Explanation with a conclusion

You are suggested to study NCERT activity 4.6 class 8 science explanation with a conclusion so that you can attempt questions based on activity 4.6 class 8 science.

Activity 4.6 Class 8 Science

   ·     Take samples of metals and non-metals listed in the table given below in separate test tubes and label them as A, B, C, D, E, and F.

   ·     With the help of a dropper add 5mL of dilute hydrochloric acid to each test tube one by one.

   ·     Observe the reactions carefully.

   ·     If no reaction occurs in the cold solution, warm the test tube gently.

   ·     Bring a burning matchstick near the mouth of each test tube.

   ·     Repeat the same activity using dilute sulphuric acid instead of dilute hydrochloric acid.

   ·     Record your observation in the table.

 

Observation of Activity 4.6 Class 8 Science

 

The reaction of metals and non-metals with acids

Test tube	Metal/non-metal	Reaction with dilute hydrochloric acid		Reaction with dilute sulphuric acid
		Room temperature	warm	Room temperature	warm
A	Magnesium	Reacts to give hydrogen	Reacts rapidly	Reacts to give hydrogen	Reacts rapidly
B	Aluminium(foil)	Reacts to give hydrogen	Reacts rapidly	Reacts to give hydrogen	Reacts rapidly
C	Iron(filings)	Almost very slow reaction	Reacts rapidly	Slow reaction	Reacts rapidly
D	Copper(peeles flexible wires)	No reaction	No reaction	No reaction	No reaction
E	Charcoal (powder)	No reaction	No reaction	No reaction	No reaction
F	Sulphur(powder)	No reaction	No reaction	No reaction	No reaction

 

Metals react with acids to form salts and hydrogen gas. When a burning matchstick is brought near the test tube, it burns with a pop sound.

 

Explanation of Activity 4.6 Class 8 Science

Metals are more highly electropositive than hydrogen so they displace hydron from acids and form soluble salts.

Metal + dil Acid Salt + Hydrogen

The reactivity decreases in the order Mg >Al> Fe> Cu

• Mg + HCl →MgCl₂ + H₂
• Mg + H₂SO₄ →MgSO₄ + H₂
• 2Al + 6HCl → 2AlCl₃ + 3H₂
• 2Al + 3H₂SO₄ →Al₂(SO₄)₃ + 3H₂
• 2Fe + 6HCl →2FeCl₃ + 3H₂
• Fe + H₂SO₄ →FeSO₄ + H₂

Copper is less reactive than hydrogen so copper does not react with acids.

Non-metals do not react with acids.

Conclusion of Activity 4.6 Class 8 Science

This activity shows the reactivity of metals and non-metals with acids.

 Related Topics 

   1. Activity 4.5 Class 8 Science

   2. Activity 4.7 Class 8 Science