Free Chemical Process Principles MCQs with Answers
2,710 Chemical Process Principles MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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- A. Polyisoprene
- B. Neoprene
- C. None of these
- D. Nitrile-butadiene
Explanation: Polyisoprene, neoprene, and nitrile-butadiene rubber are all elastomers because they undergo substantial reversible deformation.
Correct answer: None of these- A. Toluene
- B. Ethyl alcohol
- C. Naphthalene
- D. Benzene
Explanation: In the classical commercial route, benzene is catalytically oxidized to maleic anhydride, commonly using a vanadium oxide catalyst.
Correct answer: Benzene- A. Act as an acidifying agent
- B. Increase its concentration
- C. Increase the amount of molasses
- D. Increase the crystal size
Explanation: Sulfur dioxide dissolves in sugar juice and forms sulfurous acid, lowering the pH and helping clarify and preserve the juice.
Correct answer: Act as an acidifying agent- A. Furnace → evaporator → absorber
- B. Furnace → converter → absorber
- C. Furnace → converter → evaporator
- D. Converter → furnace → absorber
Explanation: Sulfur is first burned in a furnace to produce SO₂, which is oxidized to SO₃ in the converter and then absorbed to form sulfuric acid.
Correct answer: Furnace → converter → absorber- A. As an illuminant
- B. For metal cutting/welding
- C. Both A. & B.
- D. Neither A. nor B.
Explanation: Calcium carbide reacts with water to produce acetylene, a highly combustible gas.
Correct answer: Both A. & B.- A. Catalytic dehydrogenation of ethyl benzene
- B. Dehydration of ethyl alcohol followed by hydrogenation
- C. Reacting ethylene oxide with acetaldehyde
- D. Fermentation of starch
Explanation: Commercial styrene is made mainly by catalytic dehydrogenation of ethylbenzene, removing hydrogen from the ethyl side chain to form the…
Correct answer: Catalytic dehydrogenation of ethyl benzene- A. Act as optical brightening agent
- B. Prevent redeposition of soil on cleaned surface
- C. Inhibit corrosion in washing machines made of aluminium
- D. None of these
Explanation: CMC keeps loosened soil particles dispersed in the wash liquor, preventing them from settling back onto the cleaned fabric.
Correct answer: Prevent redeposition of soil on cleaned surface- A. Bauxite
- B. Boron carbide
- C. Silicon carbide
- D. Calcium carbide
Explanation: Carborundum is the commercial name for silicon carbide, SiC, a very hard abrasive material.
Correct answer: Silicon carbide- A. Hard water contains sulphate
- B. They attract back the removed dirt
- C. They form insoluble calcium soaps which precipitate
- D. None of these
Explanation: Calcium and magnesium ions in hard water react with soap to form insoluble salts, commonly called soap scum, which precipitate instead of…
Correct answer: They form insoluble calcium soaps which precipitate- A. 800
- B. 1600
- C. 4000
- D. 8500
Explanation: The turbidimetric fineness value quoted for ordinary cement is about 1600 cm²/g.
Correct answer: 1600- A. Medicated
- B. Shaving
- C. Metallic
- D. Transparent
Explanation: Phenolic antiseptics are incorporated into medicated soaps to provide germicidal action during washing.
Correct answer: Medicated- A. Na2CO3
- B. NaHCO3
- C. Na2CO3.H2O
- D. Na2CO3.10H2O
Explanation: Baking soda is sodium hydrogen carbonate, NaHCO₃. Na₂CO₃ is washing soda in its anhydrous form, while Na₂CO₃·10H₂O is washing soda crystals.
Correct answer: NaHCO3- A. All A, B. and C
- B. Silver
- C. Copper
- D. Aluminium
Explanation: Aluminium is extracted electrolytically from alumina dissolved in molten cryolite in the Hall-Héroult process.
Correct answer: Aluminium- A. Hydrogenation
- B. Hydrolysis
- C. Hydrocracking
- D. Hydration
Explanation: Hydrogenation adds hydrogen across the unsaturated bonds of vegetable oils, converting them into more saturated, solid fats.
Correct answer: Hydrogenation- A. Hydrogenation
- B. Dehydration
- C. Hydration
- D. None of these
Explanation: Quicklime is calcium oxide, and adding water converts it to calcium hydroxide, or slaked lime: CaO + H₂O → Ca(OH)₂.
Correct answer: Hydration- A. Remove residual turbidity
- B. Reduce the bacterial load on filter
- C. Control taste and odour
- D. Remove chlorinous taste
Explanation: Dechlorination removes excess residual chlorine from treated water, especially to eliminate its characteristic chlorinous taste.
Correct answer: Remove chlorinous taste- A. 0.6
- B. 1.2
- C. 2.2
- D. 3.8
Explanation: Limestone supplies most of the calcium oxide in cement, but part of its mass is lost as carbon dioxide during calcination.
Correct answer: 1.2- A. Cellulose
- B. None of these
- C. Pentogens
- D. Lignin
Explanation: Bagasse fibre contains cellulose, lignin, and pentosans, so none of the listed substances is absent.
Correct answer: None of these- A. Anthracene
- B. Creosote oil
- C. None of these
- D. Carbolic oil
Explanation: Anthracene, creosote oil, and carbolic oil are all fractions or products obtained from coal-tar distillation.
Correct answer: None of these- A. All A , B., and C.
- B. Trinitrotoluene (TNT)
- C. Cellulose nitrate
- D. Nitro-glycerine
Explanation: Nitroglycerine, TNT, and cellulose nitrate are all explosive materials.
Correct answer: All A , B., and C.