⚗️ 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

Pick out the one which is not a chemical coagulant.Answer: Chloramine Presence of iron and manganese in water causesAnswer: Discoloration of bathroom fixtures. Septic tanks are used for the __________ of the deposited solids.Answer: Anaerobic decomposition Death may occur, when SO₂ concentration in atmospheric air exceeds __________ ppm.Answer: 400 Which of the following acts as a natural source of air pollution ?Answer: Volcanic eruption Higher concentration of CO₂ in atmosphereAnswer: All (a), (b) and (c). Permissible safe limit (TLV) of __________ toxic gas is 100-1000 parts per million (ppm).Answer: Moderately Radioactive substances present in the polluted water stream can be removed byAnswer: Adsorption in ion exchange materials. In the context of the chemical process industries, the term BOD is normally associated with theAnswer: Characterisation of liquid effluents. Noise emitted by a ventilation fan at a distance of 3 metres is about __________ decibels.Answer: 105 Inhalation of silica dust causes a disease calledAnswer: Silicosis Solid content in most of the domestic sewage is about __________ percent.Answer: 0.1 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.)Answer: t = 15 + 0.0065h High noise level in a chemical plant can be controlled by theAnswer: All (a), (b) and (c). Limestone powder is injected during pulverised coal burning in boilers to __________ the flue gases.Answer: reduce SO₂ content in Main pollutants released from petroleum refineries isAnswer: CO, SO₂ & H₂S. Maximum permissible limit of industrial noise as recommended by World Health Organisation (WHO) is __________ decibels.Answer: 75 Which of the following is a green house gas other than CO₂ ?Answer: All (a), (b) and (c) Automobile exhaust is passed through two compartments catalytic converter employing platinum as catalyst forAnswer: All (a), (b) and (c). Lagooning process is mainly a means of theAnswer: Sludge disposal. Carbon monoxide is a pollutant, which causesAnswer: Asphyxiation (suffocation) leading to death. Pollution by particulate matter emission in the atmosphere does not take place during metalAnswer: Polishing Direct reaction of unsaturated hydrocarbons with either NO or NO2 produces an eye irritating pollutant compound known asAnswer: Peroxy acetyl nitrate (PAN) or methyl nitrile. BOD of raw municipal sewage may be in the range of about __________ mg/litre.Answer: 150-300 Irradiation of water by ultraviolet light of suitable wavelength is commonly used for disinfection of water inAnswer: Food industry. When the concentration of SO₂ in air is greater than __________ ppm, it gives a pungent smell.Answer: 4 Presence of a certain minimum quantity of flourine is desirable in potable water to preventAnswer: Dental cavities Pick out the wrong statement.Answer: H₂S is not at all produced during combustion of sulphur bearing fuels as all the sulphur is oxidised to SO2. Which of the following is not an air pollutant ?Answer: Ozone Presence of high concentration of ozone and smog in atmospheric air causes theAnswer: Cracking of rubber products.