Carbon dioxide dissolves in water to form carbonic acid, which is primarily dissolved co2. dissolved co2 satisfies the equilibrium equation co2(g) co2(aq) k=0.032 the acid dissociation constants listed in most standard reference texts for carbonic acid actually apply to dissolved co2. for a co2 partial pressure of 1.9x10-4 bar in the atmosphere, what is the ph of water in equilibrium with the atmosphere? (for carbonic acid ka1 = 4.46x10-7 and ka2 = 4.69x 10-11).

Explanation:

The reaction equation will be as follows.

Calculate the amount of dissolved as follows.

It is given that = 0.032 M/atm and = atm.

Hence, will be calculated as follows.

            =          

                           =

                           =

or,                        =

It is given that

As,      

                =

                      =

Since, we know that pH =

So,                      pH =

                                 = 5.7

Therefore, we can conclude that pH of water in equilibrium with the atmosphere is 5.7.