A typical pH value for rain or snow in the northeastern United States is about 4.2.

Question

Is this basic or acidic? What is the corresponding hydrogen concentration? How does this compare with the hydrogen concentration of pure water ?

Answer 1

If the pH is less than 7, it is acidic.

[H₃O⁺] = 10^-pH = 10^-4.2

The pH of pure water is 7 (i.e. neutral), so compare 10^-7 to 10^-4.2.