250+ TOP MCQs on Chemical From Sea and Answers

Chemical Industry MCQs on “Chemical From Sea”.

1. Where placer deposits of platinum can be found in sea?
a) Continental beaches
b) Deep sea floor
c) Ocean beaches
d) Subsea-floor rocks

Answer: c
Clarification: Placer deposits of platinum, gold, diamonds, limonite, magnetite, zircon, and rutile are can be found in the region of ocean beaches while phosphorite, barium, sulfate etc are can be found in the region of continental beaches.

2. Which one mentioned below is not a property of bromine extracted from sea?
a) Dark red
b) Low-boiling
c) High density
d) Low density

Answer: d
Clarification: Bromine, a dark red, low boiling and high density liquid of intensely irritating odour, is very reactive chemically, and belongs to the halogen group of elements. Thus, low density is not physical property of bromine.

3. Where the maximum amount of magnesium compounds is consumed?
a) Production of metallic magnesium
b) As insulating compounds
c) Manufacture of rubber
d) Printing ink

Answer: a
Clarification: Most of the magnesium compounds are consumed in the production of metallic magnesium. Other uses of magnesium compounds are found in refractories, insulating compounds, manufacture of rubber, pharmaceuticals etc.

4. Which process is adopted in the manufacture of magnesium compounds from sea?
a) Calcium treatment
b) Lime treatment
c) Caustic soda treatment
d) Chlorine treatment

Answer: b
Clarification: Magnesium compounds are manufactured from seawater using lime treatment. Calcium treatment is done in order to prevent low calcium level. Lime treatment process was adopted by Dow chemical company.

5. Which raw material is used in the production of crystalline magnesium chloride?
a) Seawater
b) Dolomite
c) Magnetite
d) Bitterns

Answer: d
Clarification: Crystalline magnesium chlorides are produced from the bitterns by solar evaporation. Other magnesium compounds are can be produced in addition to seawater are dolomite, magnetite etc.

6. Which by-product acids are used in the production of bromine from seawater?
a) HCl and H₂SO₄
b) HCl and HNO₃
c) HCl and H₂PO₃
d) Only HCl

Answer: a
Clarification: By-product acids HCl and H₂SO₄ are used in bromine production in order to acidify the incoming seawater. Bromine reacts with SO₂ and water and gives H₂SO₄ and HBr.

7. ”Major difficulty is in removing the ore from the seafloor to the deck” -where it appears?
a) Seafloor mining
b) Recovery from offshore placer deposits
c) Offshore mining and processing
d) Deep sea sediments

Answer: c
Clarification: The major difficulty is in this process is in removing the ore from the seafloor to the deck of the process barge. The considerable interests are seafloor phosphorite deposits on the shelves off the coasts of many nations.

8. Which composition is available in the highest amount in Indian beach sands?
a) Quartz
b) Ilmenite
c) Monazite
d) Garnet

Answer: b
Clarification: Some of the beach sands of India have the following compositions: 55.4% ilmenite, 4.1% rutile, 7% zircon, 5% monazite, 5.9% garnet, and 13.9% quartz. Recently 89% of ilmenite is being recovered.

9. What is used for bromine concentration?
a) Seawater with air
b) Seawater with HCl
c) Chlorinated seawater with air
d) Chlorinated seawater with HCl

Answer: c
Clarification: When seawater is used, bromine is first concentrated by vaporizing chlorinated seawater with air, and then SO₂ is introduced into dilute bromine laden air and is sent to an absorption tower countercurrent to water.

10. What is ‘Epsom salt’?
a) MgSO₄.7H₂O
b) MgSO₄.2H₂O
c) MgCO₂.CaCO₃
d) MgCO₂

Answer: a
Clarification: Epsom salt is MgSO₄.7H₂O. It is made by treating magnesium carbonate or hydroxide with sulfuric acid. MgCO₂.CaCO₂ is dolomite and MgCO₂ is magnetite.