250+ TOP MCQs on Inorganic Chemical – Phosphurus Industry and Answers

Chemical Industry Multiple Choice Questions on “Inorganic Chemical – Phosphurus Industry”.

1. What is IMI process in the production of phosphoric acid?
a) Wet process
b) Electric furnace process
c) Carbo-nitric process
d) Mining process

Answer: a
Clarification: Israel Mining industries=IMI process is the wet process of phosphoric acid production by hydrochloric acid leaching. In this process concentrated aqueous HCL as waste or by product acid is used.

2. In which phosphorus industry ortho and polyphosphate are used as raw materials?
a) Nitro-phosphates production
b) Sodium tripoly-phosphate production
c) Ammonium phosphates production
d) Calcium phosphate production

Answer: b
Clarification: Ortho and polyphosphate are used as raw materials in the production of sodium tripoly-phosphate. Monoammonium phosphates are used in ammonium phosphate production while phosphate rocks are used in calcium phosphate production.

3. In which phosphorous industry ‘acidulation’ reaction is occur?
a) Elemental phosphorus production
b) Phosphorus pentoxide production
c) Phosphoric acid production
d) Calcium phosphate production

Answer: d
Clarification: ‘Acidulation’ reaction is associated with calcium phosphate production. In this reaction phosphate rock reacts with aqueous H₂SO₄ and produced superphosphate and HF.

4. How triple-superphosphate is made?
a) Phosphate rock+H₂SO₄
b) Phosphate rock+HCl
c) Phosphate rock+HNO₃
d) Phosphate rock+H₃PO₄

Answer: d
Clarification: Triple-superphosphate can be made by reacting phosphate rock with phosphoric acid. It contains 42-50% P₂O₅ while ‘phosphate rock+H₂SO₄’ gives superphosphate.

5. Which one of mentioned below is not used as mined rock impurity in the production of phosphoric acid?
a) Aluminum
b) Silicon
c) Arsenic
d) Iron-oxides

Answer: c
Clarification: Except arsenic all are such as aluminium, silicon, Iron-oxide are considered as mined rock impurity. The high grade of imported ore is necessary to avoid solubilization of these mined rock impurities.

6. What is ‘merseberg process’?
a) Ammonium sulphate production
b) Calcium carbonate production
c) Sodium carbonate production
d) Sodium phosphate production

Answer: b
Clarification: In phosphoric acid production, gypsum is formed as intermediate and it can be reacted with ammonium carbonates to give ammonium sulphate (fertilizer ingredient) and calcium carbonate (merseberg process).

7. In calcium phosphate production, phosphate rock lumps are crushed in which crusher?
a) Cone crusher
b) Gyratory crusher
c) Roll crusher
d) Jaw crusher

Answer: d
Clarification: In calcium phosphate production, phosphate rock lumps are crushed in a jaw crusher and ground to 100 mesh in a hammer or ring mill and further mixed with H₂SO₄ to gives superphosphate.

8. Where ‘ammonia neutralization ‘ is done?
a) To produce nitrophosphate
b) To produce ammonium sulphate
c) To produce ammonium nitrate
d) To produce ammonium phosphate

Answer: a
Clarification: Ammonia neutralization is done in nitric acid digestion and nitric acid-sulfuric acid digestion of nitrophosphate production, where acid soluble CaHPO₄, Ca(NO₃)², NH₄NO₃ is produced.

9. What is the quantitative requirements of sulfuric acid in production of phosphoric acid?
a) 32%
b) 93-98%
c) 42-50%
d) 20%

Answer: b
Clarification: 93-98% of sulphuric acid is needed in the production of phosphoric acid, while 32% phosphate rock is needed. This sulphuric acid is reacts with Ca(PO₄)² to produce gypsum as intermediate product.