What is the role of ultraviolet (UV) radiation in water purification systems?
I. It inactivates/kills the harmful microorganisms in water.
II. It removes all the undesirable odours from the water.
III. It quickens the sedimentation of solid particles, removes turbidity and improves the water's clarity.
Which of the statement(s) given above is/are correct?
Important Questions on Chemistry
Lead, ingested or inhaled, is a health hazard. After the addition of lead to petrol has been banned, what still are lead poisoning sources?
I. Smelting units
II. Pens and pencils
III. Paints
IV. Hair oils and cosmetics
Select the correct answer using the codes given below:
Consider the following statements:
Chlorofluorocarbons, known as ozone-depleting substances, are used:
I. In the production of plastic foams
II. In the production of tubeless tyres
III. In cleaning certain electronic components
IV. As pressurizing agents in aerosol cans
Which of the statements given above is/are correct?
