⚗️ 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

Particles having diameter greater than 75 μm (micrometer = 10⁻⁶ mm) are calledAnswer: Grit Which of the following is the most severe air pollutant ?Answer: NOₓ Presence of bacteria in potable (drinking) water causesAnswer: Disease What are the methods of treatment & disposal of radioactive wastes ?Answer: All (a), (b) and (c). Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps inAnswer: All (a), (b) and (c). Main pollutant present in automobile exhaust isAnswer: CO Maximum allowable noise exposure limits for a man working for 8 hours a day in a noisy chemical plant is about __________ decibels.Answer: 120 Industrial workers working in leather tanning & manufacturing units are prone to suffer fromAnswer: Skin diseases (e.g. dermatities). Pick out the wrong statement.Answer: The characteristic of a green house body is that it allows the long wavelength incoming solar radiation to come in but does not allow the short wavelength infra red radiation to escape out of the earth's atmosphere. Peroxyacyl nitrate (PAN), a pollutant is found in theAnswer: Automobile exhaust. Foaming and priming in boiler operation can be reduced by reduction in __________ in feed water.Answer: All (a), (b) and (c). Ambient noise level can be reduced by __________ decibels by planting trees (like coconut, neem etc.) near public utility buildings (like hospitals & schools).Answer: 5-10 Pick out the wrong statement.Answer: Sulphur dioxide is the main pollutant emitted from the exhaust of petrol driven automobiles. Which of the following radioactive wastes emits all α, β & γ rays and hence is the most hazardous of all radioactive emitters?Answer: Ra-226 COD of raw municipal sewage may be in the range of about __________ mg/litre.Answer: 90-120 Maximum permissible turbidity in potable water is __________ ppm.Answer: 10 Presence of __________ hardness is responsible for the temporary hardness in water.Answer: Calcium Dose of chlorine for disinfection of water is about __________ mg/litre of water.Answer: 1 A shallow pond in which the sewage is retained and biologically treated is calledAnswer: Oxidation Which is the most practical and economical method for removal of suspended solid matter from polluted water ?Answer: Sedimentation Atmospheric pollution caused by the exhaust gas of supresonic transport air-crafts is mostly in the atmospheric region calledAnswer: Stratosphere Iron & manganese present in the polluted water is removed byAnswer: Oxidation followed by settling & filtration. Water effluent generated in printing industry is decolourised byAnswer: Electrolytic decomposition. Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of __________ present in it.Answer: Potassium cyanide __________ can not control the noise pollution.Answer: Green house gases Ozone level is generally found to be depleted in India in the month ofAnswer: December Noise level during normal conversation among men is about __________ decibles.Answer: 45 'Particulate' air pollutants are finely divided solids and liquids. Which of the following is not a 'particulate' ?Answer: None of these Foul odour and bad taste of water is removed by treating withAnswer: Activated carbon Presence of __________ in water stream are deleterious to aquatic life.Answer: All (a), (b) and (c).