Activity 2.4 Class 10 Science

The activity belongs to the chapter 2 Acids, Bases and Salts class 10 science demonstrate the chemical reaction between acid and bases.

Aim of the activity

To observe the reaction between zinc and sodium hydroxide and identify the evolving gas

Materials used in the activity

      1.  Test tubes

        2.Sodium hydroxide solution

        3.Zinc granules

        4.Beaker

        5.Dropper

        6.Soap solution

       7.Burning candle

 

Procedure

We will set the apparatus and take about 2 ml of dilute sodium hydroxide in the test tube and add a few pieces of zinc granules to it.

Activity 2.4 Class 10 Science

Through the delivery tube , pass the gas evolved to the soap solution and take a burning candle near the bubbles evolving from the soap solution.

 

Observations

On   the surface of zinc granules

We can see tiny bubble on the surface of zinc granules which indicates the reaction between base and zinc and releasing of a gas.

 

In  the soap solution

When the evolving gas is passed through the solution, the gas filled bubbles are formed.

Near the burning candle

When these gas filled bubbles come in tough with burning candle, they explode with ‘pop sound’

 

Explanation

When zinc reacts with sodium hydroxide solution, it produces salt sodium zincate  and hydrogen gas.

`2NaOH(aq)     +      Zn(s)       →    Na_2ZnO_2(aq)     +  H_2(g)`

Sodium hydroxide Zinc                  Sodium zincate

 

The hydrogen gas gets filled in the bubbles and rises in the soap solution. When a burning candle come in touch with these bubbles, they explode with pop sound.

This indicates that the evolving gas in the above reaction is ‘hydrogen gas’ because it is a highly inflammable gas.

Conclusion

The activity demonstrate that bases react with metals; such as zinc and aluminium to liberate hydrogen gas.

FAQs

   1.Why is dilute sodium hydroxide is used in this activity?

     Ans – Because concentrated NaOH reacts vigorously with zinc and the reaction release large amount of `H_2` gas and heat.

    2.What is the formula of sodium zincate?

    Ans – `Na_2ZnO_2`

   3.Why do the soap bubbles produce a pop sound when ignited?

   Ans- The soap bubbles are filled with inflammable gas hydrogen. When bubbles come in contact with flame, they burst and produce pop sound.

   4.Can other metals be used in this activity?

   Ans- Yes, the metal like aluminium can also be used in the activity.

Related Class 10 Science Activities 

 

S.No.	Topics
1	Activity 2.1
2	Activity 2.2
3	Activity 2.3
4	Activity 2.4
5	Activity 2.5
6	Activity 2.6
7	Activity 2.7
8	Activity 2.8
9	Activity 2.9
10	Activity 2.10
11	Activity 2.11
12	Activity 2.12
13	Activity 2.13
14	Activity 2.14
15	Activity 2.15