Water in contact with air is acidic, rather than neutral,

dueto dissovled carbon dioxide. Water in equilibrium with theair

contains 4.4 X 10 - 5% CO2. Theresulting

carbonic acid, H2 CO3, gives thesolution a

hydrogen ion concentration of 2.0 X10-6M, about 20

times larger than thatof pure water. Calculate the pH of the

solution.

5.7

Explanation:

The pH can be calculated by:

pH = - log[H⁺]

Where [H⁺] is the concentration of hydrogen ions. The pH is a way to identify if the solution is an acid or a base. When pH is equal to 7, the solution is neutral, when it is less than 7, it is acid, and when it is larger than 7, it's a base.

So, for the acid solution given, [H⁺] = 2.0x10⁻⁶ M

pH = - log (2.0x10⁻⁶)

pH = 5.7