Activity 14.5 Class 8 Science Chapter 14 Solution

Today we will discuss activity 14.5 class 8 science chapter 14 chemical effects of electric current.  You should also go through activity 14.4 of chapter 14. In this activity 14.5, we will discuss whether the solution of acids, bases, and salt conducts electricity or not.

 

You are suggested to study NCERT activity 14.5 class 8 science explanation with a conclusion so that you can attempt questions based on activity 14.5 class 8 science.

Activity

   ·     Take three clean plastic or rubber caps of bottles.

   ·      Pour about two teaspoonfuls of distilled water into each of them.

   ·      Add a few drops of lemon juice or dilute hydrochloric acid to distilled water in one cap.

   ·     Now in the second cap containing distilled water, add a few drops of a base such as caustic soda or potassium iodide.

   ·     Add a little sugar to the distilled water in the third cap and dissolve it.

   ·     Test which solutions conduct electricity and which do not.

   ·     What results do you obtain?

       

 Activity 14.5 Class 8 Science Chapter 14 Solution

Observation and explanation

In the previous activity 14.4, we have learnt that distilled water does not conduct electricity.

Now we add some lemon juice or HCl to distilled water in one cap.

We add NaOH or KI to the second cap and sugar to the third cap.

Now we test the all solutions one by one, which solution conducts electricity and which doesn’t?

We find that bulb glows in the first and second caps but does not glow in the third cap.

Lemon juice or HCl or NaOH gets ionized in the water so they conduct electricity.

But sugar does not get ionized so sugar solution does not conduct electricity.

Conclusion

This activity shows that water containing salt, acid, or base conducts electricity.

Frequently asked question

   1. Why sugar solution doesn’t conduct electricity?

Ans.  When sugar is added to water it does not dissociate into ions. Free ions are responsible for the conduction of electricity.

   

   2. Why does a salt solution conduct electricity?

Ans. When salt is added to water, it dissociates into ions in water. Due to free sodium and chlorine ions, the salt solution conducts electricity.

   3. Why does salt in a solid state not conduct electricity?

Ans .sodium and chlorine ions are bonded with strong bonds in the solid state of salt. There are no free ions in the solid state, that’s why it does not conduct electricity.

Related Topics

1. Activity 14.6

2. Activity 14.4