Statement I: Very little hydrogen is produced when sulphuric acid is added to calcium. Statement II: The salt that is produced, calcium sulphate, is insoluble.

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Q: 36 (NDA-II/2013)
Statement I: Very little hydrogen is produced when sulphuric acid is added to calcium. Statement II: The salt that is produced, calcium sulphate, is insoluble.

question_subject: 

Science

question_exam: 

NDA-II

stats: 

0,10,5,10,4,1,0

keywords: 

{'calcium sulphate': [0, 1, 1, 7], 'sulphuric acid': [1, 1, 0, 1], 'calcium': [2, 0, 0, 4], 'salt': [1, 0, 1, 1], 'little hydrogen': [0, 0, 0, 1]}

The correct answer is option 1 - Both the statements are individually true and Statement II is the correct explanation of Statement I.

Statement I is true because when sulphuric acid is added to calcium, only a small amount of hydrogen gas is produced. This is because calcium is not a very reactive metal and does not react vigorously with sulphuric acid to release a large amount of hydrogen.

Statement II is the correct explanation of Statement I because the salt produced when sulphuric acid reacts with calcium is calcium sulphate, which is indeed insoluble. When calcium sulphate is formed, it does not dissolve in water and therefore remains as a solid precipitate. This insolubility of calcium sulphate further limits the amount of hydrogen that can be produced in the reaction between sulphuric acid and calcium.

Therefore, both statements are true and Statement II explains why Statement I is true.