TOPIC 4: WATER

The diagram below shows a water cycle in nature. Name the processes that take place at X and Y.

• X - Condensation Y - Evaporation

• X - Evaporation Y - Freezing

• X - Evaporation Y - Condensation

• X - Evaporation Y - Evaporation

Which of the following is true about boiling and evaporation of water?

• Evaporation - takes place at all temperature

  Boiling - takes place at all temperature

• Evaporation - takes place at all temperature

  Boiling - takes place at 100C

• Evaporation - takes place at room temperature only

  Boiling - takes place at 100C

• Evaporation - takes place on hot days only

  Boiling - takes place when water is heated all the time

Figure below shows the three states of water represented by diagram X, Y and Z. Which changes occur during condensation?

• X to Y

• X to Z

• Y to X

• Z to X

Study the experiment in figure below.

At the start of the experiment, the beaker is empty. After 30 minutes, the beaker is filled with water. Which of the following explains the presence of water in the beaker?

• Water vapour is absorbed directly into the beaker from the glass bowl

• Water vapour condenses to water droplets on the plastic and fall into the beaker

• Water vapour melts into water droplets on the plastic and fall into the beaker

• Water vapour in the glass bowl rises up and fall directly into the beaker.

A solute is a substance that dissolves in a solvent to form a solution

• True

• Flase

Which of the following is the solute in carbonated (fizzy) drinks?

• Carbon dioxide

• Oxygen

• Hydrogen

• Nitrogen

Which is the correct method to separate coloured dyes?

• Chromatography

• Distillation

• Evaporation

• Filtration

A sample of ink was compared with four different dyes using chromatography. The results are shown in figure below. Which two dyes does this ink contain?

• 1 and 2

• 1 and 4

• 2 and 3

• 2 and 4

What process is used to separate a mixture of sand and water?

Name the process to obtain pure water from sea water