Air-saturated water has a hydronium ion concentration caused by the dissolved CO2 of 2.0 × 10–6 M, about 20-times larger than that of pure water. Calculate the pH of the solution at 25 °C.
Concentration of the hydronium ions caused by the dissolved CO2=2 .0×10-6M
Concentration of hydronium in pure water = 2.0×10-6 20
Therefore, Total concentration of hydronium ions=(2.0×10-6+1.0×10-7)M
pH of the solution at 25 °C is 5.68