⚗️ 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

Acute danger to human life (i.e. death) exists, if the concentration of CO₂ in atmospheric air exceeds __________ percent (by volume).Answer: 20 Methyl iso-cynate (MIC) gas (TLV <1 ppm), which caused Bhopal gas tragedy in 1984 falls under the category of __________ toxic gas.Answer: Very extremely Noise level heard inside a bus in busy city traffic or inside a sub-way train corresponds to about __________ decibels.Answer: 95 Presence of volatile compounds like gasoline, oil, alcohol, ether etc. in municipal sewers may causeAnswer: Explosion Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fanAnswer: Both (a) & (b). Presence of soluble organics in polluted water causesAnswer: Depletion of oxygen. Which of the following pollutants, if present in atmosphere is detectable by its odour ?Answer: SO₂ Exposure to chemicals having carcinogenic properties causeAnswer: Cancer In water treatment plant, zeolite process is used to remove the __________ of water.Answer: Hardness For existence of aquatic life in water, the dissolved oxygen content in it, should not be less than __________ ppm.Answer: 5 Fresh sewage is __________ in nature.Answer: Alkaline In a sedimentation tank, the detention period for water ranges from __________ hours.Answer: 2 to 4 On prolonged exposure to high concentration of carbon monoxide (> 5000 ppm), man dies becauseAnswer: It forms carboxyhaemoglobin by combining with haemoglobin of blood, thereby making it incapable of absorbing oxygen. Workers working in __________ industry are most prone to white lung cancer.Answer: Asbestos A standard test for determination of hardness in water is termed as __________ test.Answer: EDTA TLV of lead for public sewer/waste water is about __________ ppm.Answer: 1 Presence of nitrates in water in excess of 50 ppm causesAnswer: Mathenoglobenemia In sewage treatment, the detention period allowed for oxidation ponds ranges from __________ weeks.Answer: 4 to 5 Coal mines drainage waste water (acidic in nature) results from the earth's water percolating through the voids created in coal bed during mining. This polluted water which either drains out naturally to water courses or are removed before starting the mining isAnswer: Neutralised by alkali treatment. Fine grit present in sewage is removed in the __________ during sewage treatment.Answer: Detritus tank The lowest layer of atmosphere is known as theAnswer: Troposphere As per the world health organisation (WHO) specification, the maximum permissible concentration (i.e., TLV) of particulate matter in air is __________ μg/m³.(μg-microgram)Answer: 90 Which of the following is not a weightless pollutant ?Answer: SPM Global warming may result inAnswer: All (a), (b) and (c). Which of the following is the most lethal water pollutant ?Answer: Phenol and cynide Presence of carbon monoxide in atmosphere produced by decomposition of chlorophyl and haemoglobin breakdown of some animals, beyond TLV (>50 ppm)Answer: Causes asphyxia. The earth's atmosphere is an envelope of gases present upto a height of about __________ kms.Answer: 200 Which of the following is an adsorbant used for the removal of SO₂ from gas/air ?Answer: Limestone powder or alkalised alumina Higher concentration of nitrogen dioxide in atmospheric air causesAnswer: Bronchitis Ozone isAnswer: Both (b) and (c)