Given that the volume of the ocean is 1.5x10
18 m
3, net deposit of CO
2 in the ocean is 1.8144x10
15g/yr, the hydration equilibrium constant of H
2O + CO
2 H
2CO
3 is K
H=1.70x10
-3, and the acid dissociation constant of carbonic acid is K
a=4.30x10
-7. Calculate the pH after one year.
My plan to tackle this problem is to determine the moles of water and carbon dioxide, then set up equilibrium extent of reaction (E) equation for each substance. This gives me:
n
e,CO2=4.123x10
13-E
n
e,H2O=8.333x10
22-E
n
e,H2CO3=E
My question at this point is how do I account for 2:1 mole ratio of reactants and products? I need the total moles to find the partials, y
i, and I need the partials to determine the equilibrium conocentration of carbonic acid.