What is the ratio [HCO3-] / [H2CO3] in blood plasma?

The pH of Blood plasma from a pt was found to be 7.6 (not good). The principal buffer system is [HCO3-] / [H2CO3], calculate this ratio in blood plasma if the kz of H2co3 is 4.5 x 10^-7. I know the answer is about 11 or 12, but I don't know how to get there and I want to understand how to solve the problem. Will someone please help me?

Answer:
Using the Henderson-Hasselbach equation,

pH = pKa + log ([base]/[acid])

we can get to the answer. In the system in blood, the important reaction is:

H2CO3 + H2O --> HCO3- + H3O+

The HCO3- acts as the base and the H2CO3 acts as the acid. You will need to find the Ka for this reaction. (Zumdahl lists it as 4.3 x 10^-7, but your text may be slightly different)

Set the pH equal to 7.6, and insert the pKa. This will solve for the log of [HCO3-] / [H2CO3]. To find that ratio, use the inverse of the log function, (10^).

The answers post by the user, for information only, FunQA.com does not guarantee the right.

FunQA.com

What is the ratio [HCO3-] / [H2CO3] in blood plasma?

Topic