A glass of water initially at pH 7.0 is exposed to dry air at sea level at

Question:

A glass of water initially at pH 7.0 is exposed to dry air at sea level at 20°C. Calculate the pH of the water when equilibrium is reached between atmospheric CO2 and CO2 dissolved in the water, given that Henry's law constant for CO2 at 20°C is 0.032 mol/L ∙ atm.