Solutions and Solvents S1 Science ETV – The Wonderful Solvent - Water
1.Which of the following description about dissolving is NOTcorrect? When we add a solid into a liquid, the solid spreads out in the liquid. A solution is a mixture of solvent and solute. After dissolving, the solute no longer exists. Solute dissolves in solvent and disappears. It is because solute particles are too small and cannot be seen by naked eyes.
2. Which of the following affects the rate of dissolving? The size of solute particles The arrangement of solute particles. The rate of solute particles come off from the solute surface and mixes with solvent particles. The arrangement of solvent particles
3. Stirring can increase the rate of dissolving, it is because Stirring can raise the temperature of solution. Stirring allows the solvent to hold more solute particles. Stirring can make the solute particles come off from the solute surface more easily. Stirring can raise the temperature of solvent.
4. Which of the following is not an example of liquid dissolves in another liquid? Milk added to hot tea. Honey dissolves into hot water. Soy sauce dissolves in soup. Oil added to hot water.
5. Which of the following is not an example of gas dissolves in liquid? Carbon dioxide gas dissolves into water to form soft drink Oxygen dissolves into running water Presence of oxygen in the air
6. Which of the followings are dissolved in water to form coca cola? (I) and (II) only (I) and (III) only (II) and (III) only (I), (II) and (III) gas carbon dioxide (II) solid white sugar (III) concentrated solution of coca cola
7. In the process of producing coca cola, white sugar isdissolved in water of about ________℃ 20℃ 30℃ 40℃ 50℃
8. Adding sugar continuously into water until it cannot dissolve anymore, the solution formed is a _______. Syrup Saturated solution Filtrate Hot solution
9. What would happen if a saturated solution is cooled down quickly with ice water? Small and powder-like crystals will appear. As the saturated solution is cooled down, it changes into solid. The amount of water in the solution decreases, this causes the formation of crystals. Large crystals will be formed.
10. The ETV programme demonstrates growing of crystals. The name of this crystal is _______. Sodium nitrate Sodium acetate Sulphur Sodium sulphate
11. According to the ETV programme, what is the colour of cobalt (II) sulphate? White Yellow Orange Blue
12. Which of the followings are crystals we encounter in our daily life? (I) and (II) only (I) and (III) only (I), (II) and (III) only (I), (II), (III) and (IV) only (I) single crystal sugar (II) granulated sugar (III) rock sugar (IV) MSG
13. Wood is non-crystal. It is because It is not transparent The basic particles of wood are not well-aligned. It is not formed by cooling of saturated solution. Wood comes from plants and it is not chemical substance.
14. What are the criteria for natural crystals to become precious stones? (I) only (I) and (II) only (II) and (III) only (I), (II) and (III) The stone must be beautiful. (II) The stone must be durable. (III) The stone must be rare.
15. Which of the following about the formation of natural crystals is NOT correct? Precious stones originate in magma deep underneath the earth crust. Magma subjected to a long period of high pressure and temperature crystallizes slowly. Magma reaches the earth surface and becomes lava. Lava cools, precious stones are formed. Lava cooled by sea water causes the formation of precious stones.
16. Which of the following stones are classified as cubic system precious stones? (III) only (I) and (II) (I) and (III) (I), (II) and (III) (I) Garnets (II) Green sapphires (III) Diamonds (IV) Rubies
17. Which of the followings are classified as organic solvents? (I) and (II) only (I) and (III) only (I), (II) and (III) only (I), (II), (III) and (IV) only. (I) acetone (II) alcohol (III) chloroform (IV) thinner
18. Which of the followings are the characteristics of thinner? (I) and (II) only (I) and (III) only (I), (III) and (IV) only (I), (II), (III) and (IV) It can dissolve paints (II) It can dissolve acrylic sheets (III) It is highly volatile (IV) It can be used for diluting floor wax