All Free Chemical Engineering MCQs with Answers

• A. 0.5 D
• B. D
• C. 1.5 D
• D. 2 D

Explanation: For a tank with multiple impellers, the bottom impeller is commonly positioned about one impeller diameter above the tank bottom to ensure…

• A. Belt conveyor
• B. Bucket elevator
• C. Screw conveyor
• D. Apron conveyor

Explanation: Belt, bucket, and apron conveyors carry material on a belt, buckets, or plates.

• A. Packed tower
• B. Sieve tray column
• C. Bubble cap column
• D. Agitated vessel

Explanation: Oil hydrogenation requires intimate contact among oil, hydrogen gas and a solid catalyst, which is achieved in an agitated vessel.

• A. Solid dispersed in gas
• B. Solid dispersed in liquid
• C. Liquid dispersed in gas
• D. Gas dispersed in liquid

Explanation: Smoke consists of fine solid particles, such as soot, dispersed throughout a gas, usually air.

• A. Strength
• B. Thermal conductivity
• C. Electrical resistance
• D. None of these

Explanation: Moisture changes the electrical resistance of hygroscopic fibres, so fibre-resistance hygrometers can indicate humidity.

• A. Plate
• B. None of these
• C. Packed
• D. Baffle

Explanation: In the Solvay process, ammoniated brine is carbonated in a baffle-type tower, where gas-liquid contact promotes sodium bicarbonate…

• A. None of these
• B. Providing minimum percentage of voids
• C. Having maximum possible points of contact
• D. Providing irregular grain size

Explanation: Caking is promoted by close packing and many particle contacts, so minimum voids and maximum contact points are undesirable.

• A. K2CO3
• B. Ethanolamine
• C. HCl
• D. Vacuum gas oil

Explanation: Hydrogen sulfide is an acidic gas and is absorbed from reformed gas in an amine absorber, commonly using ethanolamine.

• A. 50
• B. 70
• C. 95
• D. 80

Explanation: Refined cane sugar is predominantly sucrose, commonly containing about 95% or more sucrose.

• A. All A , B. and C.
• B. After filtration, combats the corrosiveness of water due to the presence of O2 & CO2
• C. Is to adjust the pH value
• D. Before filtration, reduces the bacterial load on filters

Explanation: Hydrated lime is used to raise and adjust pH, aid water treatment before filtration, and stabilize treated water against acidity and…

• A. Phthalic anhydride
• B. Vinyl chloride
• C. Maleic anhydride
• D. Dacron

Explanation: Acetylene adds hydrogen chloride across its triple bond to form vinyl chloride, the monomer used for PVC.

• A. Pain-relieving drugs (analgesic)
• B. Plasticisers for unsaturated polyesters
• C. Pesticides
• D. Tranquilisers

Explanation: Parathion and Malathion are organophosphorus insecticides, so they belong to the pesticide group.

• A. Bromine
• B. Magnesium compounds
• C. Potassium compounds
• D. Sodium sulphate

Explanation: Bromine, magnesium compounds, and potassium salts can be recovered from concentrated seawater or brines.

• A. Fat
• B. Naphthalene
• C. Cumene
• D. Sucrose

Explanation: Glycerine is obtained industrially by hydrolysis or saponification of fats and oils, which splits triglycerides into glycerine and fatty…

• A. Bi-carbonates
• B. Sulphates & chlorides
• C. Carbonate
• D. None of these

Explanation: Permanent hardness remains after boiling and is caused mainly by soluble calcium and magnesium sulphates and chlorides.

• A. Minimises its turbidity
• B. Helps in controlling its taste and odour
• C. Minimises its corrosiveness
• D. None of these

Explanation: Dissolved oxygen accelerates corrosion of boiler and treatment equipment, so deaeration removes it and reduces corrosiveness.

• A. None of these
• B. Sequestration
• C. Scale formation
• D. Corrosion

Explanation: Dissolved oxygen acts as an oxidising agent and promotes corrosion of boiler metal, especially at elevated temperature.

• A. Low co-efficient of expansion
• B. High co-efficient of expansion
• C. High melting point
• D. Both B. and (C)

Explanation: Pyrex contains borosilicate glass, whose low coefficient of thermal expansion produces only small dimensional changes during sudden…

• A. Nicotine
• B. Caffeine
• C. Calgon
• D. Lignin

Explanation: Caffeine is a naturally occurring alkaloid and a characteristic stimulant component of coffee.

• A. Better heat & acid resistant properties
• B. Poorer resistance to alkalis
• C. All A , B. and C.
• D. Poorer dyeability

Explanation: Dacron is polyester, giving it better heat and acid resistance than nylon, but it is more vulnerable to alkalis and is harder to dye.