31. Normal rainwater is slightly acidic due to the presence of A.Carbon dioxide B.Sulphur dioxide C.Methane D.None of the above
Answer: Option A Solution: The acidity of rainwater comes from the natural presence of three substances (CO2, NO, and SO2) found in the troposphere (the lowest layer of the atmosphere). As is seen in Table I, carbon dioxide (CO2) is present in the greatest concentration and therefore contributes the most to the natural acidity of rainwater.
