Free Chemical Process Principles MCQs with Answers

• A. 250-400
• B. 50-80
• C. 1000-1200
• D. 800-900

Explanation: Yellow or white phosphorus changes to the more stable red allotrope when heated at about 250–400°C in the absence of air.

• A. P2O3
• B. P2O5
• C. PCl5
• D. H3PO4

Explanation: Phosphate fertilizers are graded by their available phosphorus expressed conventionally as equivalent P₂O₅.

• A. Fuel
• B. O2
• C. N2
• D. H2

Explanation: Naphtha is hydrocarbon feedstock that is steam-reformed to produce hydrogen-rich synthesis gas, followed by purification.

• A. Of the better CaO/SiO2 balance for slag formation
• B. CaO content is less
• C. It is cheap
• D. It produces low cost product

Explanation: In an electric furnace, the CaO-to-SiO₂ ratio influences slag formation and melting behavior.

• A. Steam reforming of naphtha and cracking of natural gas
• B. All A., B. and C.
• C. Cryogenic separation of hydrogen from coke oven gas
• D. Electrolysis of water

Explanation: Hydrogen for fertilizer plants may be obtained by reforming hydrocarbons, electrolysing water, or recovering it from coke-oven gas.

• A. Phosphorous pentoxide
• B. Ammonium phosphate
• C. Phosphorous oxychloride
• D. Calcium phosphate

Explanation: Cresylic acid reacts with phosphorus oxychloride, POCl₃, to replace the chloride groups with cresyl groups and form tricresyl phosphate.

• A. P
• B. P2
• C. P3
• D. P4

Explanation: Elemental phosphorus vapour exists mainly as tetrahedral P₄ molecules under ordinary phosphorus-vapour conditions.

• A. Urea
• B. Ammonium sulphate
• C. Superphosphate
• D. Potassium nitrate

Explanation: Ammonium sulphate is well suited to paddy because it supplies both nitrogen and sulphur and has an acidifying effect that is useful in…

• A. Salt & coke
• B. And coke
• C. Sand & coke
• D. And sand

Explanation: Phosphate rock is heated with silica sand and coke in an electric furnace.

• A. At very low pressure (vacuum)
• B. In vapour phase
• C. At very high temperature
• D. In liquid phase

Explanation: Industrial urea synthesis occurs in a liquid phase formed from ammonia and carbon dioxide, first producing ammonium carbamate and then…

• A. Electrolysis of water
• B. Steam reforming of naphtha
• C. Cracking of natural gas
• D. H2 separation from coke oven gas

Explanation: Electrolysis consumes large amounts of electrical energy to split water, making hydrogen much more expensive than hydrogen recovered from…

• A. Bicarbonate
• B. Phosphate
• C. Carbonate
• D. Silicate

Explanation: Sodium carbonate reacts with phosphoric acid to form sodium phosphate salts, with carbon dioxide and water as by-products.

• A. Nitric acid
• B. Phosphoric acid
• C. Calcium ammonium nitrate (CAN)
• D. Urea

Explanation: The Montecatini process is a high-pressure process for manufacturing urea from ammonia and carbon dioxide.

• A. All A., B. and C.
• B. Texture
• C. Water holding capacity
• D. Nutrient supply

Explanation: Biofertilisers support beneficial soil organisms and improve nutrient availability, soil structure and water retention.

• A. Increases biuret formation
• B. Decreases biuret formation
• C. Is undesirable
• D. Does not effect biuret formation

Explanation: Biuret forms when urea condenses, a reaction favoured by higher temperature and insufficient ammonia.

• A. Phosphoric acid
• B. Superphosphate
• C. Phosphorous
• D. Triple superphosphate

Explanation: Coke reduces the phosphate compounds in phosphate rock, while sand helps remove calcium as slag; the product is elemental phosphorus.

• A. 60
• B. 30
• C. 95
• D. 100

Explanation: Ammonia oxidation followed by absorption of nitrogen oxides in water commonly produces nitric acid of about 60 weight percent.

• A. All A., B. & C.
• B. High corrosion rate
• C. Increased cost of equipment
• D. Increased biuret formation

Explanation: Higher pressure and temperature improve urea conversion, but they also increase corrosion and equipment cost, while high temperature…

• A. Nitrogen
• B. Sulphur
• C. Phosphorous
• D. Potassium

Explanation: Nitrogen, phosphorus and potassium are the primary nutrients commonly guaranteed in fertilisers, whereas sulphur is needed only in certain…

• A. From coal gas (coke oven gas)
• B. By dissociating oxides of nitrogen
• C. By fractionation of liquefied air
• D. From producer gas

Explanation: Ammonia synthesis requires nitrogen from air, which can be obtained industrially by fractional distillation of liquefied air.