⚗️ 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

Algae growth in water is controlled byAnswer: Chlorination __________ is removed from water by lime-soda process.Answer: Temporary hardness Most of the bacteria in sewage areAnswer: Saprophytic Which of the following is the most major constituents of air pollutants ?Answer: Oxides of sulphur Shouting by a man at his full voice corresponds to a voice level of about __________ decibels.Answer: 80 Carbonaceous particles having size less than 1 μm are calledAnswer: Smoke __________ substances present in sewage are removed in grit chamber during sewage treatment.Answer: Inorganic The type of bacteria which is active in trickling filter during biological treatment of sewage is the __________ bacteria.Answer: Aerobic Presence of dissolved impurities of __________ is responsible for the red brownish color of water.Answer: Iron & manganese TLV of aldrin in public water supply system is about __________ μg/litre.Answer: 17 A gas is termed as non-toxic, if its maximum permissible concentration (TLV) ranges from __________ ppm.Answer: 10000 to 100000 Removal of __________ is accomplished by aeration of water.Answer: Dissolved gases Green house effect is accentuated byAnswer: All (a), (b) and (c). Thermal pollution due to excessive heat & temperature in the working place causesAnswer: All (a), (b) and (c). High concentration of carcinogenic hydrocarbon pollutants in atmospheric air causesAnswer: Cancer World environment day is observed every year on the 5th ofAnswer: June The major reason of hydrodynamic noise (i.e., noise resulting from liquid flow) isAnswer: Cavitation. The term Biological Oxygen Demand (BOD) is used in relation toAnswer: Industrial effluents The destruction of water-borne pathogens is termed as disinfection of water. Which of the following is a water disinfectant ?Answer: Chlorine Disinfection of water is done to destroy pathogenic bacteria and thus prevent water-borne diseases. Disinfection of water may be done by the use ofAnswer: All (a), (b) and (c). Which of the following processes is involved in the biochemical treatment of sewage effluents ?Answer: Oxidation Infective bacteria in water is killed by the __________ process.Answer: Sterilisation Fluorosis is caused due to the presence of excessive amount of __________ in drinking water.Answer: Fluoride Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causesAnswer: Undesirable plant growth Pick out the wrong statement.Answer: None of these The pH value of potable water should be betweenAnswer: 6.5 to 8 Maximum permissible limit of mercury in human blood is __________ micrograms/100 c.c.Answer: 7 Which of the following pollutants is absent in the emissions from a fertiliser plant ?Answer: CO Salt content in sea water is about __________ percent.Answer: 3.5 Noise level inside a jet air liner in normal flight is about __________ decibels.Answer: 100