All Free Chemical Engineering MCQs with Answers

• A. Pig iron
• B. Steel
• C. Copper
• D. Zinc

Explanation: An L.D. converter uses oxygen to remove carbon and other impurities from molten pig iron, producing steel. L.D.

• A. Limestone
• B. Soda ash
• C. Iron oxide
• D. Silica

Explanation: Ordinary soda-lime glass is made mainly from silica, soda ash and limestone.

• A. Flint
• B. Hard
• C. Soda
• D. Pyrex

Explanation: The most common glass is soda-lime glass, often shortened to soda glass.

• A. CO, CO2 N2, H2
• B. CO, H2
• C. H2, CH4
• D. C2H2, CO2, H2

Explanation: Producer gas is formed by passing air, often with steam, over red-hot carbon, so it contains chiefly CO and N₂ with smaller amounts of CO₂…

• A. Cast
• B. Wrought
• C. Pig
• D. High silicon

Explanation: Wrought iron contains very little carbon and fewer impurities than cast iron or pig iron, making it the purest traditional commercial form…

• A. Make it corrosion resistant
• B. Make glossy surface
• C. Give elasticity & prevent cracking of the film
• D. Increase atmospheric oxidation

Explanation: Plasticisers make the dried paint film more flexible by reducing brittleness, so the coating can stretch without cracking.

• A. Alumina
• B. Gypsum
• C. Ammonium bicarbonate
• D. Bauxite

Explanation: Bauxite is the usual aluminium-bearing starting material for alum manufacture; it is digested to obtain alumina, which is then converted…

• A. Slaked lime from quick lime
• B. Lime from limestone
• C. Cement
• D. None of these

Explanation: Rotary kilns calcine limestone to make quicklime and are central to cement manufacture.

• A. Electromagnetic separation
• B. Roasting
• C. Froth floatation
• D. None of these

Explanation: Roasting heats an ore in air and causes chemical reactions such as oxidation, decomposition, or sulphide conversion.

• A. 10
• B. 25
• C. 50
• D. 98

Explanation: The mercury cell produces concentrated caustic soda, typically about 50% NaOH, along with chlorine and hydrogen.

• A. Inorganic fungicide
• B. Fertiliser
• C. Insecticide
• D. Explosive

Explanation: Bordeaux mixture contains copper sulphate and lime, forming an inorganic copper fungicide used against fungal diseases of plants.

• A. Mixture of higher molecular weight alcohols (a by-product obtained during production of
• B. Extract from medicinal herbs
• C. Essential oil
• D. alcohol from molasses)
• E. None of these

Explanation: Fusel oil is a mixture of higher alcohols, especially amyl alcohols, formed as a by-product during fermentation and distillation of…

• A. Yellow
• B. Black
• C. White
• D. Blue

Explanation: Titanium dioxide is a bright white pigment with high covering power and chemical stability, which is why it is used in paints, plastics…

• A. Soda-lime
• B. Fibre
• C. Borosilicate
• D. Lead

Explanation: Lead glass, also called flint glass, has a high refractive index and is therefore useful in lenses and other optical work.

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

Explanation: Black phosphorus is the most thermodynamically stable allotrope because its layered polymeric structure is more strongly bonded than those…

• A. Sulphate
• B. Ground-wood
• C. Sulphite
• D. Semi-chemical

Explanation: Groundwood pulp is economical for newsprint because it has a high yield from wood and requires relatively inexpensive processing.

• A. Sedimentation
• B. Disinfection
• C. Coagulation
• D. Softening

Explanation: Coagulation neutralizes the charges that keep colloidal particles dispersed, allowing them to combine into larger flocs for later removal.

• A. Oxidising
• B. Reducing
• C. Disinfecting
• D. None of these

Explanation: Bleaching powder releases active chlorine, which forms oxidizing species such as hypochlorous acid in water.

• A. Detergent
• B. Rubber
• C. Pesticide
• D. Polyester

Explanation: Alkylbenzene sulfonates contain a hydrophobic alkylbenzene group and a hydrophilic sulfonate group, allowing them to remove oily dirt in…

• A. SiO2 & Al2O3
• B. CaO & SiO2
• C. CaO & Al2O3
• D. CaO & Fe2O3

Explanation: Portland cement is dominated by calcium silicates, so its principal oxide constituents are calcium oxide and silicon dioxide.