All Free Chemical Engineering MCQs with Answers

• 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.

• 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%.

• 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.

• 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.

• 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.

• 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…

• 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.

• 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.

• 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…

• 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.

• 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…

• 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…

• 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…

• 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…

• 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%.

• 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…

• 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.

• 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…

• A. Briquettes
• B. Oil gas
• C. Wood
• D. Pitch creosote mixture

Explanation: Wood is a naturally occurring fuel, whereas briquettes, oil gas, and pitch-creosote mixtures are manufactured or processed fuels.

• A. Computing the excess/deficiency of combustion air
• B. Calculation of flue gas temperature
• C. Computation of flue gas analysis
• D. None of these

Explanation: An Ostwald chart relates flue-gas composition to the amount of air supplied, allowing excess or deficient combustion air to be estimated.