Which one of the following statements best reflects the most logical, rational and practical suggestion implied by the passage?
- (a) It is a cheap and practical method to produce limestone at commercial level for building purposes.
- (b) This can be used as one of the methods of carbon sequestration. ✓ UPSC's answer
- (c) Basalt rock can be made a good source of calcium and magnesium minerals by this method.
- (d) Good rock-dissolving acid can be produced by mixing carbon dioxide and water.
Why the answer is (b)
• The passage describes a process where carbon dioxide (CO2) is injected into underground basalt rocks, causing it to react with calcium and magnesium to form limestone.
• This chemical reaction effectively converts gaseous CO2 into a solid mineral (stone), thereby removing it from the atmosphere or storage system.
• The term 'carbon sequestration' refers to the long-term capture and storage of carbon dioxide, which aligns perfectly with the described mechanism of converting CO2 into stone.
• The scientists' exclamation that 'carbon dioxide is converted into stone' highlights the permanence of this storage method, making it a logical suggestion for climate change mitigation.
• Therefore, the most logical and practical implication is that this process serves as a method for carbon sequestration.
Why the other options are wrong
- (a) It is a cheap and practical method to produce limestone at commercial level for building…
- The passage focuses on the chemical conversion of CO2 into stone as a scientific observation, not on the economic viability or commercial production of limestone for construction.
- (c) Basalt rock can be made a good source of calcium and magnesium minerals by this method.
- The process consumes calcium and magnesium from the rocks to form limestone, so it does not make basalt a source for extracting these minerals.
- (d) Good rock-dissolving acid can be produced by mixing carbon dioxide and water.
- The mixture of CO2 and water forms carbonic acid, which is weak, and the passage does not suggest producing strong rock-dissolving acids as a practical outcome.
Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2024, held on 16 June 2024. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.