What is an expression for the acid ionization constant (#K_a#) for #H_2CO_3#?

1 Answer
Jan 9, 2018

Answer:

#K_a=([H_3O^+][HCO_3^(-)])/([H_2CO_3])#

Explanation:

And this equilibrium expression represents the reaction....

#H_2CO_3(aq) +H_2O(l)rightleftharpoonsH_3O^+ + HCO_3^(-)#

Note that the existence of carbonic acid in aqueous solution may be a bit fanciful....the species in solution is likely...#H_2O*CO_2-=H_2CO_3#..i.e. carbon dioxide solvated by water. You are on your own with finding #K_a#...it is small.