3. Complete Activity 5.3 (Page 47). Take some ice in a glass or plastic tumbler. Melt a small portion of ice by placing the tumbler in the sun. You have now a mixture of ice and water. Now place the tumbler in a freezing mixture (ice plus common salt). Does the water become solid ice once again?
Answer: The above activity can be carried out as follows:
Aim: To observe if the water becomes solid ice again and make conclusions.
Material Required: Ice, glass or plastic tumbler, freezing mixture (ice plus common salt).
Procedure:
(i) Take some ice in the tumbler, place in the sun and wait for some portion of the ice to melt.
(ii) Now place the tumbler in the freezing mixture, wait for some time and observe what happens.
Observations:
After the ice-water mixture is placed in the freezing mixture, you will observe that the water becomes solid ice again.
Conclusions:
The ice solid melted and formed liquid water and then the liquid water froze back into solid ice. These indicate changes in the state of the water. Therefore, these changes are physical changes.
“Complete Activity 5.3 (Page 47). Take some ice in a glass or plastic tumbler. Melt a small portion of ice by placing the tumbler in the sun. You have now a mixture of ice and water. Now place the tumbler in a freezing mixture (ice plus common salt). Does the water become solid ice once again?” – Solved.
Related Links:
Solution to Extended Learning – Activities and Projects Question 1
Solution to Extended Learning – Activities and Projects Question 2
Solution to Extended Learning – Activities and Projects Question 3
Solution to Extended Learning – Activities and Projects Question 4
Solution to Activity 5.1
Solution to Activity 5.2
Solution to Activity 5.4
Solution to Activity 5.5
Solution to Activity 5.6
Solution to Activity 5.7
Solution to Activity 5.8
Solutions to Chapter 5 Physical and Chemical Changes
