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.

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2,710 questions · page 21 of 136

  • A. Ammonium sulphate
  • B. Calcium ammonium nitrate
  • C. Urea
  • D. Liquid ammonia

Explanation: Liquid ammonia is about 82.3% nitrogen by mass, compared with 46% in urea, about 26% in calcium ammonium nitrate and about 21% in ammonium…

Correct answer: Liquid ammonia
  • A. Increased degree of conversion of CO2 to urea
  • B. Decreased degree of conversion of NH3 to urea
  • C. Decreased yield of urea
  • D. Decreased specific volume of molten mass

Explanation: Using excess ammonia shifts the carbamate-to-urea synthesis toward greater conversion of CO2 to urea.

Correct answer: Increased degree of conversion of CO2 to urea
  • A. Phosphoric acid
  • B. Coke
  • C. Silica and coke
  • D. Sulphuric acid

Explanation: In the electric-furnace process, phosphate rock is heated with silica and coke.

Correct answer: Silica and coke
  • A. It is cheaper
  • B. It is easy to manufacture
  • C. It is not poisonous
  • D. Nitrogen content is higher

Explanation: Urea contains about 46% nitrogen, while ammonium sulphate contains about 21%.

Correct answer: Nitrogen content is higher
  • A. Avoid caking & hardening
  • B. Counteract burning
  • C. Produce bulk
  • D. Increase its solubility

Explanation: Finely divided peat acts as a conditioner by separating fertiliser particles and absorbing surface moisture.

Correct answer: Avoid caking & hardening
  • A. Water
  • B. Tar
  • C. Naphtha
  • D. Coal/coke oven gas

Explanation: Natural gas, naphtha, coal and coke-oven gas are established feedstocks for ammonia synthesis gas.

Correct answer: Tar
  • A. NO
  • B. N2H5
  • C. NO2
  • D. NH3

Explanation: Nitric acid becomes light yellow when nitrogen dioxide dissolves in it or remains as a dissolved decomposition product.

Correct answer: NO2
  • A. Calcium ammonium nitrate
  • B. Calcium nitrate
  • C. A mixture of nitric acid and lime
  • D. A mixture of ammonium nitrate and calcium nitrate

Explanation: Nitrolime is calcium ammonium nitrate, a nitrogen fertiliser made by combining ammonium nitrate with a calcium-containing material such as…

Correct answer: Calcium ammonium nitrate
  • A. Ca10(PO4)3F6
  • B. (CH3 C6 H4)3 PO4
  • C. (NH4)2HPO4
  • D. NH4H2PO4

Explanation: Tricresyl phosphate is the phosphate ester formed from three cresyl groups, giving the formula (CH₃C₆H₄)₃PO₄.

Correct answer: (CH3 C6 H4)3 PO4
  • A. Having about 40% N2
  • B. Not hygroscopic
  • C. Mixed with limestone powder to reduce its explosive nature before using it as a fertilizer
  • D. Not prone to explosive thermal decomposition

Explanation: Ammonium nitrate contains about 34.5% nitrogen, is hygroscopic, and can undergo explosive thermal decomposition.

Correct answer: Mixed with limestone powder to reduce its explosive nature before using it as a fertilizer
  • A. Phosphoric
  • B. Nitric
  • C. Sulphuric
  • D. Hydrochloric

Explanation: Triple superphosphate is produced by reacting phosphate rock with phosphoric acid, forming a concentrated product rich in available…

Correct answer: Phosphoric
  • A. Nitrogenous
  • B. Phosphatic
  • C. Potassic
  • D. None of these

Explanation: Phosphorus supports early root development and is especially associated with seed and fruit formation.

Correct answer: Phosphatic
  • A. Urea
  • B. Calcium cyanamide
  • C. Ammonium sulphate
  • D. CAN

Explanation: Calcium cyanamide supplies nitrogen, acts as a weed suppressant in crops such as onions, and its alkaline action helps correct acidic…

Correct answer: Calcium cyanamide
  • A. Meta
  • B. Ortho
  • C. Pyro
  • D. None of these

Explanation: H₄P₂O₇ is pyrophosphoric acid, commonly called pyro phosphoric acid. Orthophosphoric acid is H₃PO₄, while metaphosphoric acid has the…

Correct answer: Pyro
  • A. None of these
  • B. Superphosphate
  • C. Triple superphosphate
  • D. Ammonium phosphate

Explanation: Ammonia neutralises orthophosphoric acid to form ammonium phosphate, chiefly monoammonium or diammonium phosphate depending on the…

Correct answer: Ammonium phosphate
  • A. Oxidation of ammonia
  • B. CaNO3 + H2SO4 reaction
  • C. Passing air through high voltage electric arc
  • D. None of these

Explanation: Commercial nitric acid is made by the Ostwald process, in which ammonia is catalytically oxidised to nitric oxide, then further oxidised…

Correct answer: Oxidation of ammonia
  • A. 10
  • B. 46
  • C. 80
  • D. 94

Explanation: Urea, CO(NH₂)₂, contains two nitrogen atoms and has a nitrogen content of about 46.6% by mass, conventionally stated as 46%.

Correct answer: 46
  • A. Urea
  • B. Calcium ammonium nitrate (CAN)
  • C. Ammonium nitrate
  • D. Ammonium sulphate

Explanation: Ammonium nitrate, NH₄NO₃, contains approximately 35% nitrogen by mass. Urea contains about 46%, ammonium sulphate about 21%, and CAN is…

Correct answer: Ammonium nitrate
  • A. Produce seedless fruit
  • B. Cause early maturation of plants
  • C. Accelerate ripening of food and grain
  • D. Hold back stem growth and halt plants at a desired height

Explanation: Plant tranquillisers are growth retardants that suppress stem elongation, allowing the plant to remain at a controlled height.

Correct answer: Hold back stem growth and halt plants at a desired height
  • A. Hydrogen peroxide, air and water
  • B. Anhydrous ammonia, air and water
  • C. Anhydrous ammonia and air
  • D. Wet ammonia, air and water

Explanation: The Ostwald process uses anhydrous ammonia and air for catalytic oxidation, followed by absorption of the nitrogen oxides in water to…

Correct answer: Anhydrous ammonia, air and water