All Free Chemical Engineering MCQs with Answers

• A. Lead oxide
• B. Silica
• C. Alumina
• D. Soda

Explanation: Flint glass is distinguished from ordinary soda-lime glass by its high lead oxide content, which gives high refractive index and…

• A. Ethyl alcohol
• B. Both A. & B.
• C. Ethylene
• D. Neither A. nor B.

Explanation: SBR is made from the monomers butadiene and styrene; historically, ethanol can serve as a source of butadiene, while ethylene can lead to…

• A. Oxidising
• B. Reducing
• C. Complex forming
• D. Photochemical

Explanation: Thiosulphate forms a soluble complex with silver halide, dissolving the unexposed silver salts from photographic film during fixing.

• A. Cationic
• B. Semi polar
• C. Amphoteric
• D. Anionic

Explanation: Alkyl benzene sulfonates contain a negatively charged sulfonate group, so they are anionic detergents.

• A. Phosgene
• B. Calcium hypochlorite
• C. Chlorine
• D. Ammonium chloride

Explanation: Chloroform is produced from acetone by chlorination with bleaching powder, whose active component is calcium hypochlorite.

• A. Red
• B. Violet
• C. Yellow
• D. Black

Explanation: Yellow, or white, phosphorus has a strained molecular structure and is much more reactive than the polymeric red, violet, and black forms.

• A. None of these
• B. Acidic
• C. Neutral
• D. Alkaline

Explanation: Kraft pulping uses sodium hydroxide and sodium sulfide in an alkaline liquor to dissolve lignin from wood.

• A. Remove impurities/gangue
• B. Enhance rate of reaction
• C. Accelerate reduction of ore
• D. Separate slag from metal

Explanation: Flux combines with gangue and other impurities during smelting to form slag, thereby removing them from the ore.

• A. Diatomaceous earth
• B. Activated carbon
• C. Bauxite
• D. Bentonite

Explanation: Activated carbon adsorbs the coloured impurities present in yellow glycerine, after which filtration produces white glycerine.

• A. Chromium
• B. Arsenic
• C. Copper
• D. Manganese

Explanation: Copper oxide imparts blue to greenish-blue shades to glass, depending on its concentration and oxidation state.

• A. Inversion
• B. Hydration
• C. Esterification
• D. None of these

Explanation: Hydrolysis of sucrose produces glucose and fructose and is called inversion because the optical rotation of the solution changes sign.

• A. Increase its thickness
• B. Impart resistance to penetration by liquids
• C. Increase its flexibility & opacity
• D. Increase its brightness

Explanation: Sizing fills or coats the pores of paper so that water, ink, and other liquids do not penetrate readily.

• A. Ambient temperature fluctuation
• B. Water to cement ratio
• C. Sand to cement ratio
• D. Drying period

Explanation: Cement shrinkage is strongly affected by water-cement ratio, drying time, and temperature conditions.

• A. Cold lime process
• B. Coagulation
• C. Sequestration
• D. Hot-lime soda process

Explanation: The hot lime-soda process is widely used to soften boiler feed water because heating accelerates reactions that precipitate calcium and…

• A. Filtration
• B. Boiling
• C. None of these
• D. Distillation

Explanation: Distillation removes both dissolved bicarbonates responsible for temporary hardness and soluble sulphates or chlorides responsible for…

• A. Cl2, H2 & NaOH solution
• B. Cl2 & H2
• C. O2 & H2
• D. Cl2 & Na

Explanation: At the anode, chloride ions form chlorine, while water at the cathode forms hydrogen and hydroxide ions.

• A. H2SO3
• B. H2S2O7
• C. H2SO4
• D. H2SO7

Explanation: Oleum is fuming sulphuric acid, produced by dissolving sulphur trioxide in sulphuric acid.

• A. Eliminates absorber
• B. Yields acids of lower concentration than chamber process
• C. Is obsolete
• D. Yields acid of higher concentration than chamber process

Explanation: The contact process produces concentrated sulphuric acid, commonly about 98%, whereas the chamber process gives a much more dilute acid.

• A. Citrus fruits
• B. Controlling poultry lice
• C. Potato beetle
• D. Controlling timber degradation by ants

Explanation: Hydrogen cyanide has been used as a fumigant against insect pests on citrus plants and fruits.

• A. Corundum
• B. Viscose rayon
• C. Plasticiser for unsaturated polyester
• D. Paints

Explanation: Carbon disulphide reacts with cellulose to form cellulose xanthate, the intermediate used in manufacturing viscose rayon.