All Free Chemical Engineering MCQs with Answers

• A. DDT
• B. BHC
• C. Parathion
• D. None of these

Explanation: Chloral condenses with chlorobenzene in the presence of an acid catalyst to form DDT.

• A. Oil of vitriol
• B. Muriatic acid
• C. Strong organic acid
• D. Green acid

Explanation: Hydrochloric acid is the aqueous solution of hydrogen chloride and is traditionally called muriatic acid.

• A. Amorphous isotropic material
• B. Supercooled liquid
• C. Material with sharp definite melting point
• D. Electrical insulator

Explanation: Ordinary glass is amorphous, isotropic and electrically insulating, and it softens over a temperature range rather than having a sharp…

• A. 1
• B. 2.5
• C. 5
• D. 10

Explanation: Approximately 2.5 tons of bamboo or wood are needed to produce one ton of dry paper pulp because much of the raw material is removed as…

• A. Higher melting point & higher reactivity to oxygen
• B. Lower melting point & higher reactivity to oxygen
• C. Lower melting point & lower reactivity to oxygen
• D. Higher melting point & lower reactivity to oxygen

Explanation: Double bonds in unsaturated oils lower the packing efficiency of their chains, reducing the melting point, and provide reactive sites for…

• A. Polyvinyl chloride (PVC)
• B. Polybutadiene
• C. Phenol formaldehyde
• D. Polyurethane

Explanation: Bakelite is a thermosetting resin formed by condensation of phenol with formaldehyde.

• A. Tissue
• B. Board
• C. Ground-wood
• D. Wrapping

Explanation: Groundwood paper is inexpensive and has a high yield because it retains much of the wood, making it suitable for newsprint.

• A. C + H2O = CO + H2
• B. CaC2 + H2O = Ca(OH)2 + C2H2
• C. MgCO3 = MgO + CO2
• D. All (A), B. and (C)

Explanation: The reaction of calcium carbide with water releases heat during formation of calcium hydroxide and acetylene.

• A. Carbon tetrachloride
• B. Chlorobenzene
• C. Ethylene dichloride
• D. Chlorinated paraffin

Explanation: Carbon tetrachloride can undergo high-temperature pyrolysis or chlorinolysis to form tetrachloroethylene, also called perchloroethylene.

• A. Carbonates
• B. Bicarbonates
• C. Phosphates
• D. Sulphates

Explanation: Temporary hardness is caused by soluble calcium and magnesium bicarbonates, which decompose on boiling to form insoluble carbonates.

• A. A black, sticky & viscous liquid
• B. Used in the manufacture of greases, emulsions & soaps
• C. All A , B. & C.
• D. Composed mainly of rosin & fatty acids

Explanation: Tall oil is a dark, sticky liquid recovered from black-liquor soap and contains mainly rosin and fatty acids.

• A. Arc process of nitric acid manufacture is economical as compared to Ostwald's process
• B. It is a strong mono basic acid which reacts with almost all the metals except noble metals
• C. Yellow color of impure nitric acid is because of dissolved oxides of nitrogen (mainly NO2)
• D. About 90% of nitric acid is manufactured by Ostwald's process

Explanation: The arc process is generally uneconomical compared with the Ostwald process because it requires very high temperatures and consumes much…

• A. Semi-drying oil
• B. Non-drying oil
• C. Drying oil

Explanation: Drying oils oxidise and polymerise in air to form a hard protective film, which is essential in paints and varnishes.

• A. In the manufacture of hydrogen bomb
• B. As a fissile fuel in a nuclear reactor
• C. For the manufacture of gas mantles
• D. In the treatment of cancer

Explanation: Thorium compounds were historically used in incandescent gas mantles because thorium oxide produces a bright, heat-resistant glow.

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

Explanation: Coagulation, sedimentation and disinfection are standard steps in conventional potable-water treatment.

• A. Precipitation
• B. Dispersion
• C. Emulsification
• D. Wetting

Explanation: Soap or detergent cleaning depends on wetting the soil, dispersing particles and emulsifying oily matter.

• A. Density
• B. Physical state
• C. Chemical properties
• D. Composition

Explanation: The usual distinction is physical state: oils are liquid at ordinary temperature, whereas fats are solid or semi-solid.

• A. N2 & H2
• B. CO2 & H2
• C. CO & H2
• D. C & H2

Explanation: Synthesis gas for producing methanol, hydrogen and other chemicals consists primarily of carbon monoxide and hydrogen, with their…

• A. Anti soil redeposition agent
• B. Builder
• C. Optical brightening agent
• D. Surfactant

Explanation: CMC forms a protective film on fabric and prevents loosened dirt from settling back onto it during washing.

• A. Not a fumigant
• B. BHC (Benzene Hexachloride) containing 99% γ-isomer
• C. A by-product of BHC manufacture
• D. Both B. and C.

Explanation: Lindane is the nearly pure gamma isomer of BHC, usually containing about 99% gamma-HCH.