chemical engineering chemical environmental engineering chemical engineering MCQs – Page 9

Practise multiple-choice questions from chemical engineering chemical environmental engineering chemical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering chemical environmental engineering chemical engineering Mcqs
161. Radioactive substances present in the polluted water stream can be removed by_________________?
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A. Coagulation and filtration

B. Biological oxygen treatment

C. Adsorption in ion exchange materials

D. None of these

162. Presence of nitrogen in high concentration in contaminated air reduces partial pressure of oxygen in lungs, thereby causing asphyxia (suffocation) leading to death from oxygen deficiency. Concentration of N2 in contaminated air at which it acts as a natural asphyxiate is ? _____________ percent?
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A. 88

B. 92

C. 84

D. 80

163. Fresh sewage is ______________ in nature?
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A. Acidic

B. Alkaline

C. Neutral

D. Highly acidic

164. What are the methods of treatment & disposal of radioactive wastes ?
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A. Evaporation & chemical precipitation

B. Fixing into a solid mass with cement and sinking deep in the sea

C. All A., B. & C.

D. Biological methods & adsorption in ion exchange materials

165. Which of the following causes death by asphyxiation, if its presence in atmospheric air exceeds maximum allowable concentration (i.e. > 50 ppm) ?
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A. Carbon monoxide

B. Sulphur dioxide

C. Peroxyacetyl nitrate

D. Benzopyrene

166. When the concentration of SO2 in air is greater than ______________ ppm, it gives a pungent smell?
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A. 0.1

B. 4

C. 1

D. 0.01

167. Fluorosis is caused due to the presence of excessive amount of ______________ in drinking water?
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A. Fluoride

B. Lead

C. Arsenic

D. Mercury

168. In large thermal power stations very fine particulates present in flue gas are removed by___________________?
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A. Dust catcher

B. Wet scrubber

C. Bag filter

D. Electrostatic precipitators
169. Maximum permissible residual chlorine in treated water should be ____________ mg/litre?
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A. 2 to 3

B. 0.2 to 0.3

C. 0.001 to 0.01

D. 5 to 10

170. Pick out the wrong statement pertaining to green house for the plants ?
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A. Green house is colder than the outside atmosphere

B. acts like the glass of green house thereby warming up the earths surface

C. e ultra-violet rays) to pass through the glass and heat up the soil thereby warming up plants

D. The emitted longer wavelength radiation (e.g., infrared) is partly reflected and partly absorbed

E. Green house effect in earths atmosphere is due to increasing CO2 level in atmosphere, where

F. ide it

171. Foul odour and bad taste of water is removed by treating with__________________?
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A. Activated carbon

B. Copper sulphate

C. Bleaching powder

D. Alum

172. TLV of ammonia, nitrogen dioxide and phenol vapor in air is ______________ ppm ?
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A. 5

B. 1000

C. 100

D. 2000

173. Which of the following is the most severe air pollutant ?
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A. Hydrocarbons

B. NOx

C. CO

D. SO2

174. World environment day is observed every year on the 5th of___________________?
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A. December

B. June

C. July

D. September

175. A gas is termed as non-toxic, if its maximum permissible concentration (TLV) ranges from ______________ ppm?
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A. 1000 to 2000

B. 10000 to 100000

C. 6000 to 9000

D. 3000 to 6000

176. Presence of high concentration of ozone and smog in atmospheric air causes the __________________?
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A. Fading of dye on textiles

B. Cracking of rubber products

C. Embrittlement & decrease of folding resistance of paper

D. Damage of electrical insulator on high tension power line

177. Noise level in a quiet private business office is about _____________ decibels?
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A. 25

B. 85

C. 50

D. 70

178. Fine grit present in sewage is removed in the _____________ during sewage treatment?
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A. Detritus tank

B. Trickling filter

C. Grit chamber

D. Skimming tank

179. Scale formation in boiler is controlled by____________________?
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A. Preheating of feed water

B. Reduction in hardness, silica & alumina in feed water

C. Keeping the pH value of feed water just below 7

D. Eliminating H2S in feed water

180. Which is the most widely used coagulant for the treatment of turbid water ?
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A. Alum (aluminium sulphate)

B. Sodium aluminate

C. Ferric chloride

D. Lime