⚗️ Chemical Engineering Solved MCQs with Answers

Practice 1920 approved ⚗️ Chemical Engineering questions with verified answers from the 🛠️ Engineering Essentials subject for Pakistan exams.

1920 solved MCQs

A 'body' which allows the short wavelength incoming solar radiation to enter in, but does not allow long wave length outgoing infra red radiation to escape out is called theAnswer: Green house Fresh domestic sewage is __________ in color.Answer: Grey The common pollutant generated in chlor-alkali industry and battery manufacture isAnswer: Mercury During sewage treatment, the sewage is subjected to __________ treatment in Imhoff tank.Answer: Both (b) and (c) Black smoke coming out of the chimney of a furnace is an indication of the use of __________ in the furnace.Answer: Low amount of excess combustion air Pick out the wrong statement.Answer: A bag filter incurs very small pressure drop and is very efficient for removal of sub-micronic dust particles from flue gases at very high temperature. __________ content of the phosphate rock is the pollutant of primary interest in a phos-phatic fertiliser plant.Answer: Fluorine Beyond what concentration of H₂S in air, acute danger to human life exists ?Answer: 700 ppm Reingleman chart is used for the evaluation of __________ pollution.Answer: Air There are five concentric layers within the atmosphere which is differentiated on the basis of temperature. The atmospheric layer which lies close to the earth's surface in which human being along with other organisms live is called troposphere. The rate at which air temperature in the troposphere gradually decreases with height is about __________ °C/km.Answer: 6.5 Brown spots in fabrics will be caused by washing with water containing large amount of .Answer: Iron Maximum permissible concentration (i.e. TLV) of DDT in public water supply system is __________ micro gram (μ g)/litre.Answer: 42 Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric air's water vapor condenses on the solid particles of smoke thereby forming smog (smoke + fog), it causesAnswer: All (a), (b) and (c). Deaeration of high pressure boiler feed water is done to reduceAnswer: Its dissolved oxygen content. Exposure to SO₂ containing chimney gases results in theAnswer: All (a), (b) and (c). The detrimental effect on organism and water quality with temperature rise of aquatic system is the reduction of __________ of water.Answer: Dissolved oxygen content Hydrogen ion concentration in distilled water isAnswer: 10−7 Out of the following, TLV of __________ is maximum (about 500 ppm).Answer: Carbon dioxide Which of the following plants does not emit appreciable amount of SO₂ in atmosphere ?Answer: Nitric acid plant The maximum CO₂ is emitted into the atmosphere byAnswer: Combustion Which of the following is not a practical method of low level radioactive waste disposal ?Answer: Filling in steel crates and shooting it off out of earth's gravity. Major sources of noise in furnace operation arises from air inspirators, combustion, side wall vibrations and fluctuation in the process heat load. A 50% increase in fuel firing rate may increase the furnace noise level by about __________ decibels.Answer: 3 Removal of __________ results from the disinfection of water.Answer: Bacteria 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 ?Answer: CO Carcinogenic air pollutants causeAnswer: Cancer Inhalation of silica dust by human being during hand drilling in mica mining, lead & zinc mining, silica refractory manufacture and in foundaries causesAnswer: All (a), (b) and (c). Soluble silica present in boiler feed water can be removed byAnswer: Anion exchanger Presence of non-biodegradable substances, like alkyl benzene sulphonate (ABS) from the detergents in polluted water stream causesAnswer: Persistent foam. Pick out the wrong statement.Answer: The concentric layer in atmosphere which contains about 70% of the total mass of atmosphere and characterised by a steady decrease in temperature is called stratosphere. Radioactive solid nuclear wastes are disposed off byAnswer: Underground burial in concrete containers.