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Science and Technology › Chemistry
Indiscriminate disposal of used fluorescent electric lamps causes mercury pollution in the environment. Why is mercury used in the manufacture of these lamps ?
(a)
A mercury coating on the inside of the lamp makes the light bright white
(b)
When the lamp is switched on, the mercury in the lamp causes the emission of ultra-violet radiations
(c)
When the lamp is switched on, it is the mercury which converts the ultra-violet energy into visible light
(d)
None of the statement given above is correct about the use of mercury in the manufacture of fluorescent lamps
(B)
Chlorination is a process used for water-purification. The disinfecting action of chlorine is mainly due to
the formation of hydrochloric acid when chlorine is added to water
the formation of hypochlorous acid when chlorine is added to water
the formation of nascent oxygen when chlorine is added to water
the formation of hydrogen when chlorine is added to water
If a potato is placed on a pure paper plate which is white and unprinted and put in a microwave oven, the potato heats up but the paper plate does not. This is because:
Potato is mainly made up of starch whereas paper is mainly made up of cellulose
Potato transmits microwaves whereas paper reflects microwaves
Potato contains water whereas paper does not contain water
Potato is a fresh organic material whereas paper is a dead organic material.
(C)