Activity 9.1 Let us investigate (Page 136) Class 8
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Activity 9.1 Let us investigate (Page 136) Class 8
Activity 9.1 Let us investigate (Page 136) Class 8
Take a clean glass tumbler and fill it half with water.
Add one spoon of salt into it and stir well till it dissolves completely.
Gradually add a spoonful of salt into the glass tumbler and stir.
Observe how many spoons of salt you can add before it stops dissolving completely.
Record your observations in the Table.
Table 9.1 Dissolution of salt in water
| Amount of salt taken (teaspoon) | Observation (salt dissolves/ salt does not dissolve) |
| One | Salt dissolves |
| Two | Salt dissolves |
| Three | Salt dissolves |
| Four | Salt does not dissolve (some salt settles at bottom) |
| Five | Salt does not dissolve (some settles at bottom) |
Observation: Only a few spoons of salt could be dissolved before some of it remained undissolved.
Conclusion: Water has a high capacity to dissolve salts.
Explanation:
- Water has a limit to how much salt it can hold-this is called its saturation point. Once reached, extra salt just settles at the bottom.
- Stir well after each spoon and observe closely. We can even use a transparent glass to see the undissolved salt.