The [H+] in the acid rain which has a pH of 5.6 is Hydrogen ion which dissociates from the acidic Carbonic acid.
Explanation:
- Pure water is neutral (pH=7). However, the pH of natural, unpolluted rainwater is 5.6 which is acidic. The rainwaters acidity is from SO₂, CO₂, and NO and these are three substance which is found in the lowermost layer of the atmosphere.
- Carbonic acid formed by the reaction of CO₂ and water which then dissociates to give the hydrogen ion (H+) and the hydrogen carbonate ion (HCO₃-). The ability of H₂CO₃ to deliver H+ says this molecule as an acid.
CO₂ + H₂O ----> H₂CO₃
H₂CO₃ ----------> [H+] + [HCO₃-]
Using the equation,
pH = - log [H+] , we can solve for [H+] as following,
- pH = log [H+] ,
[H+] = 10-pH,
Exponentiating on both sides with base 10. The hydrogen ion concentration is,
[H+] = 10-5.6 = 0.0000025 = 2.51 × 10-6 M.
