E. Answer the following questions.
1. Why do solids have a fixed shape and a definite volume?
2.
Briefly describe an activity to show that pure water is a transparent liquid.
3.
Describe an activity to show that a solid can diffuse slowly into a liquid.
What is a 'saturated solution'? How can one prepare a saturated solution of
common salt in water?
5. Suggest one activity to show the effect of temperature on the solubility of a solid
in water.
Answers
Answer:
1. Solids possess a fixed shape and a fixed volume because their is a strong intermolecular forces of attraction between the particles of matter.
2. Activity:
- Take a bowl/beaker half filled with pure water and place a lemon in the bowl/beaker containing water.
- Keep it undisturbed for a few minutes in a place where there is enough light.
- Now observe the immersed lemon from the top of the bowl/beaker.
- Observation:
It is observed that the lemon is visible clearly from the top.
- Conclusion:
Pure water is a transparent liquid.
3. Activity:
- Take a beaker and fill it half with water (liquid).
- Put 2-3 crystals of potassium permanganate (solid) in it.
Observation:
- We would observe that potassium permanganate (which is a solid), gets dissolved in water (which a liquid).
Conclusion:
- Solid can diffuse in liquid.
4. At any particular temperature, a solution that has dissolved as much solute as it is capable of dissolving, is said to be saturated solution.
Refer to the activity below to understand how can one prepare a saturated solution of common salt.
Activity:
- Take approximately 50 mL water in a beaker.
- Add some salt in the beaker while stirring continuously.
- When no more solute(salt) can be dissolved, heat the beaker.
- Start adding solute again while stirring continuously.
Observation:
- We would obseve that no more salt further can be added to the beaker.
Conclusion:
- The salt solution is saturated.
5. Activity:
- Take a beaker and fill it half with water.
- Put some common salt in the beaker continuously till the solution becomes saturated.
- Stop adding more salt once the solution becomes saturated.
- Once the solutions become saturated, heat the content of the beaker.
Observation:
- We could observe that the salt has been dissolved evenly in the solution and that the solution a no longer saturated as the temperature is increased.
Conclusion:
- The Solubility of solid in water increases as the temperature increases.
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hope it's helpful
Answer:
T have fixed shape and different volume because it particle have very tightly packed