chemical engineering Mcqs
7901. Ethanolamine is an absorbent used for the removal of _____________ from air/gas?
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A. HF

B. SO2

C. H2S

D. Both B. & C.
7902. Which of the following gases is having the widest explosion limit (about 2 to 81% gas in gasair mixture), rendering it the property of the most explosive gas ?
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A. Ammonia

B. Hydrogen

C. Acetylene

D. Carbon monoxide

7903. _____________ plant emits large amount of SO2 as an air pollutant?
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A. Iron & steel

B. Nitric acid

C. Chlor alkali

D. Sulphuric acid
7904. Fine grit present in sewage is removed in the _____________ during sewage treatment?
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A. Trickling filter

B. Grit chamber

C. Skimming tank

D. Detritus tank
7905. Which is the most practical and economical method for removal of suspended solid matter from polluted water ?
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A. Sedimentation

B. Biological oxidation

C. Chlorination

D. Skimming off

7906. Foul odour and bad taste of water is removed by treating with__________________?
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A. Activated carbon

B. Bleaching powder

C. Alum

D. Copper sulphate

7907. ______________ cannot control the noise pollution ?
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A. Use of silencers

B. Vibration damping

C. Green house gases

D. Tree plantation

7908. Pick out the wrong statement. A. Caustic embrittlement of boilers metallic parts is caused by high concentration of caustic soda in boiler feed water___________________?
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A. Cooling and freezing of water kills the bacteria present in it

B. Dissolved oxygen content in high pressure boiler feed water should be nil

C. ica in feed water goes on decreasing

D. With increasing boiler operating pressure of steam, the maximum allowable concentration of

7909. Inhalation of silica dust causes a disease called__________________?
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A. Silicosis

B. None of these

C. Bronchitis

D. Pneumoconiosis

7910. A considerable part of the harmful ultraviolet radiation of the sum does not reach the earth surface, because of the fact that, there is a layer of _____________ high above earths atmosphere, which absorbs it?
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A. Carbon dioxide

B. Hydrogen

C. Ozone

D. None of these

7911. Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal ?
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A. By chemical coagulation

B. In sedimentation tanks equipped with mechanical scrapper

C. In clarifiers

D. In vacuum filter

7912. Dissolved oxygen content in river water is around _____________ ppm?
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A. 5

B. 100

C. 500

D. 250

7913. Presence of ____________ in water stream are deleterious to aquatic life?
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A. Heavy metals and cyanides

B. Soluble and toxic organics

C. Suspended solids

D. All A., B. & C.
7914. Inorganic impurities causing water pollution is ____________________?
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A. Protein

B. Fats

C. Salts of metals

D. Carbohydrates

7915. Most efficient and suitable dust removal equipment for removal of fly-ash from flue gas in a thermal power plant is the__________________?
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A. Cyclone separator

B. Gravity settling chamber

C. Bag filter

D. Electrostatic precipitator
7916. Removal of ______________ is accomplished by aeration of water?
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A. Dissolved solids

B. Suspended solids

C. None of these

D. Dissolved gases
7917. Bag filter design is predominantly dependent on gas temperature, as it affects the gas density & viscosity and the selection of filtering material. The pressure drop in a bag filter is__________________?
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A. Inversely proportional to viscosity of gas

B. Proportional to the viscosity & density of the gas

C. Proportional to the pressure of the gas

D. Both B. and C.
7918. The main industrial source of emission of hydrogen sulphide air pollutant is________________?
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A. Petroleum refineries

B. Metallurgical roasting & smelting plant

C. Coal based thermal power plants

D. Pulp and paper plant

7919. Turbidity of water is an indication of the presence of__________________?
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A. Suspended inorganic matter

B. Dissolved gases

C. Floating solids

D. Dissolved solids

7920. TLV of ozone (O3) and phosgene (COCl2) in air is _______________ ppm?
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A. 0.1

B. 25

C. 1000

D. 100

7921. Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10C, doubles the toxic effects of _____________ present in it?
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A. Coal ash

B. None of these

C. Potassium cyanide

D. Ortho-xylene

7922. Out of the following, TLV of _______________ is maximum (about 500 ppm)?
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A. Acetaldehyde

B. Carbon dioxide

C. Carbon disulphide

D. Toluene

7923. 5-200 ?m size particles are called__________________?
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A. Dust

B. Colloids or aerosols

C. Powder

D. Smoke

7924. Noise emitted by a ventilation fan at a distance of 3 metres is about _____________ decibels?
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A. 125

B. 85

C. 105

D. 145

7925. Pick out the wrong statement?
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A. orosis

B. Loamy soil is the best soil for vigorous plant growth, while the clayey soil is solid and hence

C. Large excess use of nitrogenous fertiliser in land causes the problem of diarrhoea and cyanosis

D. plant roots penetrate with difficulty

E. Cereal crops grown on alkaline soil absorb higher amount of fluorides thereby spreading

F. Application of large excess of Potassic fertiliser in soil increases the valuable carotene in
7926. 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. Benzopyrene

D. Peroxyacetyl nitrate

7927. The most commonly used chemical coagulant in water treatment is________________?
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A. Lime

B. Hydrazine

C. Ferrous sulphate

D. Alum
7928. Main pollutants released from iron & steel industry is__________________?
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A. CO, CO2 & SO2

B. SO3, NO2 & CO2

C. CO2, H2S & NO2

D. H2S, NO & SO3

7929. Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric airs water vapor condenses on the solid particles of smoke thereby forming smog (smoke + fog), it causes_________________?
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A. Poor visibility due to sky darkening

B. All A., B. and C.

C. Respiratory trouble

D. Irritation in eyes

7930. Which of the following plants does not emit appreciable amount of SO2 in atmosphere ?
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A. Nitric acid plant

B. Thermal power plant

C. Petroleum refinery

D. Sulphuric acid plant

7931. Aerodynamic noise resulting from turbulent gas flow is the most prevalent source of valve noise in fluid flow control. It is caused due to_________________?
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A. Reynold stresses

B. Shear forces

C. Both A. & B.

D. Neither A. nor B.

7932. When a gas is subjected to adiabatic expansion, it gets cooled due to__________________?
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A. Decrease in temperature

B. Decrease in kinetic energy

C. Energy spent in doing work

D. Decrease in velocity

7933. BOD of raw municipal sewage may be in the range of about _____________ mg/litre?
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A. 10-May

B. 2-Jan

C. 150-300

D. 2000-3000

7934. Maximum permissible turbidity in potable water is _____________ ppm?
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A. 1

B. 250

C. 10

D. 1000

7935. Septic tanks are used for the ______________ of the deposited solids?
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A. Separation

B. Anaerobic decomposition

C. Aerobic decomposition

D. None of these

7936. Atmospheric pollution caused by the exhaust gas of supersonic transport air-crafts is mostly in the atmospheric region called________________?
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A. Troposphere

B. Thermosphere

C. Stratosphere

D. Mesosphere

7937. Foaming and priming in boiler operation can be reduced by reduction in ______________ in feed water?
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A. Total solids

B. Color (Hazen)

C. All A., B. & C.

D. Turbidity

7938. Phenolic water generated in coke ovens & by-product plant attached to an integrated steel plant containing phenol in concentration of less than 100 mg/litre can be removed by_______________?
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A. None of these

B. Chlorination

C. Chemical coagulation

D. Treating in biological oxygen pond
7939. Which of the following is the most efficient for removal of very finely divided suspended solids and colloidal matter from the polluted water stream ?
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A. Circular clarifier

B. Chemical coagulation

C. Mechanical flocculation

D. Sedimentation tank

7940. Worlds worst radioactive pollution was caused by nuclear reactor disaster which occured in ___________________?
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A. Arizona (U.S.A.)

B. Moscow (U.S.S.R.)

C. Chernobyl (undivided U.S.S.R.)

D. Pennsylvania (U.S.A.)

7941. The progressive warming up of the earths surface is mainly due to the___________________?
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A. Blanketing effect of CO2 in the atmosphere

B. De-forestation

C. Automobile exhaust

D. Thickening of ozone layer

7942. Chemical potential (an intensive property) of a substance is a force that drives the chemical system to equilibrium and is equal to its partial molar properties. The ratio of chemical potential to free energy of a pure substance at constant temperature and pressure is________________?
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A. None of these

B. 1

C. 0

D. ?

7943. Automobile exhaust is passed through two compartments catalytic converter employing platinum as catalyst for___________________?
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A. Conversion of NOx into N2 and NH3 in the first compartment

B. All A., B. and C.

C. Conversion of CO into CO2 in the second compartment

D. Oxidation of unburnt hydrocarbon fuel in the second compartment

7944. Inhalation of lead compounds present in automobile exhaust (using leaded petrol) causes__________________?
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A. All A., B. & C.

B. Blood poisoning

C. Nervous system disorder

D. Anaemia

7945. The density of the gases (present in air) decreases with increasing altitude to such an extent, that about 70% of the mass of atmospheric air is found in the lower 5 km. of the atmosphere. This lower region of atmosphere is called the_________________?
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A. None of these

B. Ionosphere

C. Troposphere

D. Stratosphere

7946. Presence of high concentration of ozone and smog in atmospheric air causes the __________________?
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A. Embrittlement & decrease of folding resistance of paper

B. Cracking of rubber products

C. Fading of dye on textiles

D. Damage of electrical insulator on high tension power line

7947. Carbon monoxide is a pollutant, which causes_________________?
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A. Asphyxiation (suffocation) leading to death

B. Damage to building materials like marble

C. Retardation in crop growth

D. Respiratory disease (e.g. asthma)

7948. As per the world health organisation (WHO) specification, the maximum permissible concentration (i.e., TLV) of particulate matter in air is _____________ ?g/m3.(?g-microgram)?
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A. 750

B. 10

C. 90

D. 800

7949. Pick out the correct statement ?
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A. COD is related to BOD of a given waste in water but the relationship varies for different

B. hromate in cone, sulphuric acid solution at boiling temperature for specified time

C. tes. Typically COD of potable water may be 1-2 mg/litre

D. Chemical oxygen demand (COD) is a measure of chemically oxidisable organic matter present

E. water

F. COD is determined by oxidising the organic matter present in water with potassium

7950. 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 15C and t is in C ?
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A. t = 15 + 0.0065h

B. t = 0.0035h -15

C. t = 15 0.0065h

D. t = 15 0.0035h