Question 47 of 48
Q.The pH of normal rain water is :
(a) 6.5
(b) 7.5
(c) 5.6
(d) 4.6
Tamil Nadu DgeTamil Nadu HSC First Year (DGE) Board 2026MCQ· 1mImportance★★★★★est
98% · 47/48 Questions
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Start your 14-day free trial to unlock the full solution →The question asks for the pH of normal rain water.
Normal rain water has a pH of about 5.6, because dissolved atmospheric CO2 makes it weakly acidic.
Pure water is neutral with a pH of 7. However, rain water is never truly pure: as it falls it dissolves atmospheric carbon dioxide, which reacts with water to form carbonic acid:
CO2 + H2O ⇌ H2CO3 …
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