Question

The ph of blood plasma from a patient was found to be 7.6 a life-threatening situation. Calculate the ration (HCO3-)/(H2CO3) in this sample of blood plasma. (Ka of H2CO3, carbonic acid, is 4,5×10^-7

Answer 1

To calculate the ratio (HCO3-)/(H2CO3) in this sample of blood plasma use the Henderson-Hasselbach equation,

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

given that;

pH of blood plasma = 7.6

Ka of H2CO3, carbonic acid, is 4.5×10^-7

Therefore; pKa = - log Ka

= - log 4.5×10^-7

= 6.4

Then;

pH = pKa + log (HCO3-)/(H2CO3)

7.6 =6.4 + log (HCO3-)/(H2CO3)

log (HCO3-)/(H2CO3) =1.2

(HCO3-)/(H2CO3) = 10^1.2

(HCO3-)/(H2CO3) = 15.85

Hence the ratio (HCO3-)/(H2CO3) in this sample of blood plasma is 15.85