1. What method is used to obtain salt from sea water? a. decantation c. evaporation b. sedimentation d. filtering
2. Which of the following examples undergo evaporation process? a. a pail of water under the heat of the sun b. brushing your teeth after meal c. ironing clothes every weekend d. listening to the radio
3. It is the main factor that causes evaporation process in separating mixtures. a. water c. smoke b. heat d. light
4. Princess accidentally spill a glass of water in the salt container and she is thinking with of a solution on how she’s going to recover salt from water. What will Princess do to return the salt to its original phase? a. She will wrap it with newspaper tightly b. She will throw it away in the waste can c. She will hide it in a dark corner d. She will boil the solution
5. While boiling water in a kettle, Gwayne noticed that there are smoke coming from the spout of a kettle. He asked his mother, “Why did the smoke rise upward”? What do you think will be the mother’s answer? a. because the water reached its cooling point b. because the water reached its boiling point c. because the water is heated and became water vapor d. because the water is freezing
Write E if the following conditions undergo the evaporation technique of separating mixtures and N if not.
6. water in the canal becomes less after the rain - ___________
7. doormat on the floor - ___________
8. wet hair becomes dry - ___________ 9. chair on the ground - ___________
10. cooling after sweating - ___________
Answers & Comments
1. [C.] evaporation
2. [A.] a pail of water under the heat of the sun
3. [B.] heat
4. [D.] she will boil the solution
5. [C.] because the water is heated and became water vapor
6. E
7. N
8. E
9. N
10. N
Explanation:
1. Since salt and seawater is a true solution, you'll have to use evaporation to separate the two. For those thinking filtration would work, it would not.
2. For evaporation, you need to use heat to do that particular separation method. The sun generate heat so yeah, then the water would evaporate from it.
3. The water molecules move rapidly when the water is heated. This makes the molecules escape faster. Higher temperatures lead to increase in vaporization as more molecules get kinetic energy to convert into vapor. For example, boiling water evaporates faster than fresh tap water.
4. Its just like the answer from question 1.
5. If you boil some water you will notice that just above the bubbling water you can see nothing. As the steam rises it cools, condenses and becomes visible again like white smoke.
6. The water became less after the rain in the canal, not only its being led probably somewhere to distribute those dumps of water away but the ones that was remained would be also affected by the sun's heat afterwards.
7. It did not specify that the floor nor the doormat was wet. So I assume they are already dry. You would have nothing on those two objects that would be affected by evaporation.
8. Ah yes, the hair affected by water which was wet would be dry using heat.
9. Just like the answer on question 7.
10. There is no heat used, you are just cooling but that is the opposite of heat. Thus you are not using evaporating anything. Those sweat either get absorbed or you just wipe them off.