Explore topic-wise MCQs in Chemical Engineering.

This section includes 444 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.

351.

_Algae growth in water is controlled by$?

A. Deoxidation
B. Chlorination
C. Bleaching
D. Aeration
Answer» C. Bleaching
352.

_Presence of __________ bacteria in water causes disease like typhoid.$?

A. Aerobic
B. Pathogenic
C. Anaerobic
D. Non-pathogenic
Answer» C. Anaerobic
353.

_Smog is not formed due to the presence of __________ in the atmosphere.$?

A. SO‚ÇÇ
B. NOx
C. CO‚ÇÇ
D. Any of these
Answer» D. Any of these
354.

_Very small amount of air pollutants are present in stratosphere also; though most of the atmospheric pollutants are present in the troposphere. Which of the following atmospheric pollutants does not cause the ozone layer depletion in atmosphere at tremendous rate?$?

A. CO
B. SO‚ÇÇ
C. NOx
D. CFC (chloro fluoro carbons)
Answer» B. SO‚Äö√á√á
355.

_The destruction of water-borne pathogens is termed as disinfection of water. Which of the following is a water disinfectant?$?

A. Chlorine
B. Alkalis
C. Benzene hexachloride
D. Alkyl benzene sulphonate (ABS)
Answer» B. Alkalis
356.

_The pH value of oxidised sewage is about$?

A. 1.8
B. 6.2
C. 7.3
D. 13.4
Answer» D. 13.4
357.

_A gas is termed as non-toxic, if its maximum permissible concentration (TLV) ranges from __________ ppm.$?

A. 1000 to 2000
B. 3000 to 6000
C. 6000 to 9000
D. 10000 to 100000
Answer» E.
358.

_Tolerable limit of nitrogen oxides in air is __________ ppm.$?

A. 0.1
B. 1
C. 5
D. 25
Answer» D. 25
359.

_Iron & manganese present as pollutant in water can not be removed by$?

A. Ion exchange process
B. Oxidation followed by settling & filtration
C. Lime soda process or manganese zeolite process
D. Chlorination
Answer» E.
360.

_Lung cancer & DNA breakage are the major ill effects of excessive ozone exposure to human beings. Ozone layer depletion in the atmosphere is mainly caused by the presence of$?

A. CO‚ÇÇ
B. SO‚ÇÇ
C. Hydrocarbons
D. CFC (chloro fluoro carbon)
Answer» E.
361.

_Which is a secondary air pollutant?$?

A. Photochemical smog
B. Sulphur dioxide
C. Nitrogen dioxide
D. Dust particles
Answer» B. Sulphur dioxide
362.

_Direct reaction of unsaturated hydrocarbons with either NO or NO‚ÇÇ produces an eye irritating pollutant compound known as$?

A. Photochemical smog
B. Peroxy acetyl nitrate (PAN) or methyl nitrile
C. Benzopyrene
D. Poly acrylonitrile
Answer» C. Benzopyrene
363.

_Threshold limit value (TLV) i.e., the maximum permissible safe limit of phosgene gas which Hitler used to use to kill his enemies in 'gas chamber' is about __________ ppm.$?

A. <1
B. 10-100
C. 100-200
D. 100-1000
Answer» B. 10-100
364.

_Presence of non-biodegradable substances, like alkyl benzene sulphonate (ABS) from the detergents in polluted water stream causes$?

A. Fire hazards
B. Explosion hazards
C. Persistent foam
D. Depletion of dissolved oxygen
Answer» D. Depletion of dissolved oxygen
365.

_Which of the following is not a practical method of low level radioactive waste disposal?$?

A. Dilution with inert material
B. Discharging to atmosphere through tall stacks after dilution
C. Disposing off in rivers & oceans
D. Filling in steel crates and shooting it off out of earth
Answer» E.
366.

_In troposphere (the weather domain), the temperature 't' at height 'h' above the spa level in metres is given by (where, temperature at sea level is 15°C and t is in °C.)$?

A. t = 15 - 0.0065h
B. t = 15 + 0.0065h
C. t = 0.0035h -15
D. t = 15 - 0.0035h
Answer» B. t = 15 + 0.0065h
367.

_Fresh sewage is __________ in nature.$?

A. Acidic
B. Neutral
C. Alkaline
D. Highly acidic
Answer» D. Highly acidic
368.

_The main type of sludge gas evolved during sewage treatment in Imhoff tank is$?

A. CO‚ÇÇ
B. CH‚ÇÑ
C. CO
D. H‚ÇÇ
Answer» C. CO
369.

_Green house effect is accentuated by$?

A. Deforestation
B. Rapid industrialisation
C. Increased transportation activity
D. All of the above
Answer» E.
370.

_Lead exhausted in the atmosphere by automobiles using leaded petrol (i.e. tetraethyl lead for improving octane number) is a lethal air pollutant which causes$?

A. Paralysis of muscles & loss of appetite
B. Nervous depression
C. Gastritis & diarrhea
D. All of the above
Answer» E.
371.

_Which of the following is not a source of ozone emission in the atmosphere?$?

A. Refrigerators
B. Xerox machines
C. Dermatological photo-therapy equipments
D. High voltage electrical equipments
Answer» B. Xerox machines
372.

_Irradiation of water by ultraviolet light of suitable wavelength is commonly used for disinfection of water in$?

A. Food industry
B. Municipal sewage treatment
C. Petroleum refinery
D. Iron & steel plant
Answer» B. Municipal sewage treatment
373.

_Particles having diameter greater than 75 μm (micrometer = 10-6 mm) are called$?

A. Grit
B. Dust
C. Powder
D. Smoke
Answer» B. Dust
374.

_A shallow pond in which the sewage is retained and biologically treated is called$?

A. Oxidation
B. Imhoff tank
C. Lagoon
D. Skimming tank
Answer» B. Imhoff tank
375.

_Disinfection of water is done to destroy pathogenic bacteria and thus prevent water-borne diseases. Disinfection of water may be done by the use of$?

A. Ozone and iodine
B. Chlorine or its compounds
C. Ultraviolet light for irradiation of water
D. All of the above
Answer» E.
376.

_White smoke coming out of the chimney of a furnace indicates the use of$?

A. Low excess air
B. Very high excess air
C. Gaseous fuel in the furnace
D. Liquid fuel in the furnace
Answer» C. Gaseous fuel in the furnace
377.

_Presence of soluble organics in polluted water causes$?

A. Undesirable plants growth
B. Depletion of oxygen
C. Fire hazards
D. Explosion hazards
Answer» C. Fire hazards
378.

_Maximum permissible limit of mercury in human blood is __________ micrograms/100 c.c.$?

A. 1
B. 7
C. 19
D. 82
Answer» C. 19
379.

_TLV of NO‚ÇÇ & NO exposure for the human being is 5 & 25 ppm respectively. Prolonged exposure of human being to NO‚ÇÇ causes$?

A. Skin disorder
B. Bronchitis
C. Bone disease
D. Cancer
Answer» C. Bone disease
380.

_The upper layer of atmosphere is called the$?

A. Stratosphere
B. Troposphere
C. Ionosphere
D. None of these
Answer» B. Troposphere
381.

_Radioactive solid nuclear wastes are disposed off by$?

A. High temperature incineration
B. Pathological incineration
C. Pyrolysis
D. Underground burial in concrete containers
Answer» E.
382.

_Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causes$?

A. Foaming
B. Odour nuisances
C. Undesirable plant growth
D. Turbidity
Answer» D. Turbidity
383.

_Exposure to chemicals having carcinogenic properties cause$?

A. Dermatitis (skin disorder)
B. Cancer
C. Asphyxiation
D. Asthma
Answer» C. Asphyxiation
384.

_Threshold Limit Value (TLV) is the maximum allowable concentration (i.e. safe limit) of pollutants in air. Safe limit for SO‚ÇÇ in air is __________ ppm.$?

A. 5
B. 500
C. 1000
D. 2000
Answer» B. 500
385.

_In a sedimentation tank, the detention period for water ranges from __________ hours.$?

A. 2 to 4
B. 8 to 12
C. 16 to 20
D. 24 to 32
Answer» B. 8 to 12
386.

_Septic tanks are used for the __________ of the deposited solids.$?

A. Separation
B. Anaerobic decomposition
C. Aerobic decomposition
D. None of these
Answer» C. Aerobic decomposition
387.

_Peroxyacyl nitrate (PAN), a pollutant is found in the$?

A. Automobile exhaust
B. Flue gas of coal based power plant
C. Exhaust of nitric acid plant
D. Exhaust of sulphuric acid plant
Answer» B. Flue gas of coal based power plant
388.

_Limestone powder is injected during pulverised coal burning in boilers to __________ the flue gases.$?

A. Reduce SO‚ÇÇ content in
B. Catalytically convert SO‚ÇÇ to SO‚ÇÉ in
C. Increase the dew point of
D. None of these
Answer» B. Catalytically convert SO‚Äö√á√á to SO‚Äö√á√â in
389.

For existence of aquatic life in water, the dissolved oxygen content in it, should not be less than __________ ppm.$?

A. 10000
B. 5
C. 500
D. 1000
Answer» C. 500
390.

Which of the following air pollutants is not toxic to vegetation i.e., doesn't cause vegetation damage?$?

A. Smog & ozone
B. Hydrogen fluoride & nitrogen oxides
C. Sulphur dioxide & spray of weed killers
D. Carbon monoxide
Answer» E.
391.

Maximum permissible residual chlorine in treated water should be __________ mg/litre.$?

A. 0.001 to 0.01
B. 02 to 0.3
C. 2 to 3
D. 5 to 10
Answer» C. 2 to 3
392.

The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the$?

A. Bacterial stability factor
B. Relative stability
C. Biological oxygen demand (BOD)
D. Oxygen ion concentration
Answer» C. Biological oxygen demand (BOD)
393.

In the context of the chemical process industries, the term BOD is normally associated with the$?

A. Characterisation of solid wastes
B. Organic concentration in gaseous effluents
C. Characterisation of liquid effluents
D. Characterisation of boiler feed water
Answer» D. Characterisation of boiler feed water
394.

Most of the bacteria in sewage are$?

A. Parasitic
B. Saprophytic
C. Anerobic
D. None of these
Answer» C. Anerobic
395.

Shouting by a man at his full voice corresponds to a voice level of about __________ decibels.$?

A. 25
B. 50
C. 80
D. 120
Answer» D. 120
396.

A standard test for determination of hardness in water is termed as __________ test.$?

A. EDTA
B. Electometric
C. Total count
D. Presumptive
Answer» B. Electometric
397.

Presence of carbon monoxide in atmosphere produced by decomposition of chlorophyl and haemoglobin breakdown of some animals, beyond TLV (>50 ppm)$?

A. Acts as a green house gas thereby raising earth's temperature
B. Causes asphyxia
C. Causes increase in sea level
D. Inhances the green house effect
Answer» C. Causes increase in sea level
398.

Noise emitted by a ventilation fan at a distance of 3 metres is about __________ decibels.$?

A. 85
B. 105
C. 125
D. 145
Answer» C. 125
399.

Turbidity of water is an indication of the presence of$?

A. Suspended inorganic matter
B. Dissolved solids
C. Floating solids
D. Dissolved gases
Answer» B. Dissolved solids
400.

The principal gas evolved from sludge digestion tank is$?

A. CO
B. CO‚ÇÇ
C. CH‚ÇÑ
D. N‚ÇÇ
Answer» D. N‚Äö√á√á