All Free Chemical Engineering MCQs with Answers

• A. Anti-redeposition agent
• B. Cleaning power booster
• C. Corrosion inhibitor
• D. Fabric brightener

Explanation: Builders improve detergent performance by softening water, maintaining alkalinity, and helping remove soil, so they act as cleaning-power…

• A. High cost of mercury
• B. High specific gravity of mercury
• C. Pollution of water stream by mercury
• D. Non-availability of high purity mercury

Explanation: Mercury leakage can contaminate wastewater and create serious environmental and health hazards, making pollution the major disadvantage of…

• A. Blue pigment
• B. Synthetic resin
• C. Artificial abrasive
• D. Refractory material

Explanation: Kaolin is a clay mineral, mainly hydrated aluminium silicate, and is widely used in refractory products because it withstands high…

• A. Rock phosphate
• B. Chalcopyrite
• C. Cryolite
• D. None of these

Explanation: Phosphoric acid is manufactured industrially from phosphate rock, commonly by reacting it with sulfuric acid in the wet process.

• A. Slag cement
• B. Teflon
• C. Porcelain/Potteries
• D. Glasses

Explanation: Teflon is polytetrafluoroethylene, an organic fluoropolymer, so it is not a ceramic material.

• A. Phosphoric acid
• B. Phosphorous
• C. All A , B. and C
• D. Superphosphates

Explanation: Phosphate rock supplies phosphorus for phosphoric acid and elemental phosphorus production, and it is also reacted with acids to make…

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

Explanation: Cement contains the most CaO, while SiO2 is generally the second-largest oxide by mass. Al2O3 and Fe2O3 are present in smaller proportions.

• A. C+ ½O2 = CO
• B. CaCO3 = CaO + CO2
• C. CO + 3H2 = CH4 + H2O
• D. CO + ½O2 = CO2

Explanation: The decomposition of calcium carbonate requires heat, so CaCO3 → CaO + CO2 is endothermic.

• A. Benzol-toluol-xylol
• B. Benzol-toluene-xylene
• C. Benzene-toluene-xylene
• D. Benzene-toluol-xylol

Explanation: BTX is the standard abbreviation for benzene, toluene and xylene, the principal aromatic products recovered from coal-tar or petroleum…

• A. Its calorific value is very less
• B. It reduces viscosity and imparts fluidity for its transportation through pipelines at economic
• C. Tar neutralises the residual acids present in pitch
• D. pressure drop
• E. All A, B. and C.

Explanation: Pitch is highly viscous at ordinary temperatures, so mixing it with creosote oil lowers its viscosity and makes pumping through pipelines…

• A. Both B. and C.
• B. Allotrope of carbon
• C. Moderator used in nuclear reactor
• D. Electrical insulator

Explanation: Graphite is an allotrope of carbon and is also used as a moderator because its carbon nuclei slow neutrons effectively.

• A. Methyl alcohol
• B. Hydrochloric acid
• C. Nitric acid
• D. Formic acid

Explanation: A small addition of nitric acid lowers the freezing point of 35% oleum and helps prevent solidification during winter transport.

• A. Cermet
• B. Explosive
• C. Abrasive
• D. Cement

Explanation: Cement is produced from finely ground calcium silicates and calcium aluminates, which hydrate and harden after mixing with water.

• A. 102 - 107
• B. 105 - 109
• C. 102 - 102
• D. 109 - 1011

Explanation: Polymer molecules commonly have molecular weights extending from roughly 10^2 or 10^3 up to about 10^7, depending on the polymer and…

• A. Anthracite
• B. Sub-bituminous
• C. Lignite
• D. Peat

Explanation: Anthracite is the highest-rank coal listed, with the greatest carbon content and therefore the highest calorific value.

• A. H2SO4 by Chamber process
• B. Hydrochloric acid
• C. Calcium carbide
• D. Corundum

Explanation: A Mannheim furnace reacts sodium chloride with concentrated sulphuric acid to produce hydrochloric acid and sodium sulphate.

• A. Flocculate the impurities
• B. Facilitate fast filtration
• C. Both A. and B.
• D. Neither A. nor B.

Explanation: Lime neutralizes acidic impurities and promotes their coagulation or flocculation in sugar juice, producing a precipitate that can be…

• A. SO3
• B. SO2
• C. NH3
• D. Cl2

Explanation: Chlorine oxidizes bromide ions in the hot mother liquor to liberate elemental bromine: 2Br⁻ + Cl₂ → Br₂ + 2Cl⁻.

• A. 25°C, 2 atm
• B. 50°C, l0 atm
• C. 30°C, 200 mm Hg (absolute)
• D. 90°C, 45 atm

Explanation: Penicillin fermentation is carried out at a mild temperature near 25°C under aerobic conditions; the other listed temperatures and…

• A. Bacteria
• B. Undesirable taste and odour
• C. Bicarbonates & sulphates of calcium and magnesium
• D. Its corrosiveness

Explanation: The lime-soda process softens water by precipitating calcium and magnesium as carbonates and hydroxides, removing their bicarbonates and…