Quiz Chapter 5: Water and Solution

1. What is the role of Slaked Lime (calcium hydroxide) in the municipal water treatment plant?

1. To neutralize acidic water and lower its acidity
2. To kill harmful microorganisms
3. To filter out large plant debris
4. To add mineral taste to tap water

2. How does a larger exposed surface area affect wet clothes drying on a clothesline?

1. Decreases evaporation because more area absorbs moisture
2. Increases evaporation rate by allowing more surface water molecules to escape
3. Has no effect on evaporation rate
4. Prevents wind from reaching the fabric

3. Why is pure water considered a compound rather than an element or mixture?

1. It consists of two elements (Hydrogen and Oxygen) chemically combined in a fixed ratio
2. It can be separated physically using filter paper
3. It has variable boiling points depending on stirring
4. It contains floating suspended particles

4. Which condition describes a saturated solution at room temperature?

1. It contains very little solute and can dissolve much more solute
2. It contains the maximum amount of dissolved solute; any additional solute will not dissolve
3. It contains no dissolved solute particles
4. It consists only of liquid organic solvents

5. Why does fine sugar dissolve faster in warm water than coarse sugar crystals in cold water?

1. Fine sugar has a smaller total surface area and higher temperature slows down dissolution
2. Higher temperature increases kinetic energy and smaller particle size increases total surface area
3. Coarse sugar crystals react chemically with cold water to slow dissolution
4. Warm water reduces the solubility limit of sugar

6. Which factor decreases the rate of evaporation of water exposed in an open environment?

1. Higher surrounding temperature
2. Higher atmospheric humidity
3. Faster wind speed
4. Larger exposed surface area

7. What is the primary purpose of adding Alum during the water purification treatment process?

1. To kill pathogenic bacteria and viruses
2. To cause fine suspended particles to clump together (coagulation)
3. To reduce acidity and adjust water pH
4. To prevent dental caries in the population

8. What is the volume ratio of Hydrogen to Oxygen gas produced during the electrolysis of pure water?

1. 1 : 1
2. 1 : 2
3. 2 : 1
4. 3 : 1

9. What type of mixture is formed when chalk powder is shaken vigorously with water and left to stand?

1. Dilute solution
2. Saturated solution
3. Suspension
4. Colloid

10. Why is water commonly referred to as a 'universal solvent'?

1. It can dissolve every existing substance on Earth
2. It can dissolve a wider variety of substances than any other liquid solvent
3. It is the only liquid that forms neutral solutions
4. It boils at exactly 100°C under all circumstances