Science Hm4-Chemistry Physics

The diagram shows the process of water treatment in a treatment plant.

Which method is correctly matched with its purpose?

• P : Filtration ; Q: Sedimentation ; R: Chlorination

• P: Sedimentation ; Q: Coagulation ; R: Filtration

• P: Filtration ; Q: Coagulation ; R: Chlorination

• P: Coagulation ; Q: Sedimentation R: Filtration

What is the purpose of adding alum in a water treatment factory? A. B. C. D.

• to prevent tooth decay

• to kill the microorganisms

• to coagulate the suspended particle

• to reduce acidity of water

Which of the following represent rare gases?

I. helium II. Neon III. Argon IV. Radon

• I, II, III only

• I, III, IV only

• II, III, IV only

• I, II, III and IV

Alum added in a water treatment plant during…

• Filtration stage

• Sedimentation stage

• Coagulation stage

• Chlorination stage

Of the following types of water, which can lather easily with soap?

• Well water

• Sea water

• Lake water

• Rain water

________ is a colourless gas with a strong and pungent smell. It is used to make fertilizers and nitric acid. A. B. C. D.

• Ammonia

• Oxygen

• Nitrogen

• Neon

Which of the following statements about nitrogen is correct?

• It is colourless with slightly sour taste.

• It is easily soluble in water.

• The boiling point of nitrogen is -183°C

• It can’t burn and doesn’t support burning.

The lightest rare gas is________.

• hydrogen

• nitrogen

• helium

• neon

Which of the following gas is used in food packaging in order to keep the food fresh?

• oxygen

• nitrogen

• neon

• calcium

What is the correct term for plants loss water from their leaves through the stomata, which then evaporates?

• Evaporation

• Precipitation

• Transpiration

• Condensation