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.

Last updated

2,710 questions · page 102 of 136

  • A. Bauxite
  • B. Quartz
  • C. Limestone
  • D. Manganese

Explanation: Limestone acts as the flux in a blast furnace. It decomposes to lime, which combines with silica and other earthy impurities to form a…

Correct answer: Limestone
  • A. Usually soft soap (made from coconut oil) in which cane sugar & alcohol are added and
  • B. finally washed with methylated spirit to achieve transparency
  • C. Metallic soaps with frothing agent and free Stearic acid to achieve transparency
  • D. Metallic soaps with frothing agent from which glycerine has not been recovered
  • E. None of these

Explanation: Transparent soaps are produced by incorporating materials such as alcohol, sugar and glycerine into soap, which reduces crystal formation…

Correct answer: Usually soft soap (made from coconut oil) in which cane sugar & alcohol are added and
  • 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.

Correct answer: 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.

Correct answer: 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…

Correct answer: Material with sharp definite melting point
  • 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…

Correct answer: 2.5
  • 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…

Correct answer: Lower melting point & higher reactivity to oxygen
  • A. Polyvinyl chloride (PVC)
  • B. Polybutadiene
  • C. Phenol formaldehyde
  • D. Polyurethane

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

Correct answer: Phenol 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.

Correct answer: Ground-wood
  • 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.

Correct answer: CaC2 + H2O = Ca(OH)2 + C2H2
  • 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.

Correct answer: Carbon tetrachloride
  • 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.

Correct answer: Bicarbonates
  • 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.

Correct answer: All A , B. & C.
  • 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…

Correct answer: Arc process of nitric acid manufacture is economical as compared to Ostwald's process
  • 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.

Correct answer: Drying oil
  • 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.

Correct answer: For the manufacture of gas mantles
  • A. Coagulation
  • B. Sedimentation
  • C. Disinfection
  • D. Softening

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

Correct answer: Softening
  • A. Precipitation
  • B. Dispersion
  • C. Emulsification
  • D. Wetting

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

Correct answer: Precipitation
  • 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.

Correct answer: Physical state
  • 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…

Correct answer: CO & H2