UPSC Prelims 2024 · CSAT

Question 51: Reading Comprehension

Passage beginning “When an international team of scientists…” — Passage—1 · as printed by UPSC

Which one of the following statements best reflects the most logical, rational and practical suggestion implied by the passage?

aIt is a cheap and practical method to produce limestone at commercial level for building purposes.

bThis can be used as one of the methods of carbon sequestration.

cBasalt rock can be made a good source of calcium and magnesium minerals by this method.

dGood rock-dissolving acid can be produced by mixing carbon dioxide and water.

AnswerUPSC’s answer is (b).

The passage describes carbon dioxide mixed with water and pumped into basalt, where the acidic mixture dissolves calcium and magnesium out of the rock and locks the carbon away as limestone: carbon dioxide turned into stone. The practical idea this implies is storing carbon dioxide safely underground, i.e. carbon sequestration. Producing limestone for building, the minerals in basalt and a rock-dissolving acid are details of the chemistry, not the practical suggestion.

Why each option is right or wrong

(a) Wrong. The passage does not claim this is a cheap way to make limestone for construction.
(b) Right. Turning carbon dioxide into stone stores it, which is carbon sequestration.
(c) Wrong. Calcium and magnesium are part of the process, but supplying minerals is not the point.
(d) Wrong. An acidic mixture is part of the chemistry, but it is not the practical suggestion.

Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.

Practise this paper timedPrevious question Next question

Source: UPSC, Civil Services (Preliminary) Examination 2024, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.