The analytical concentration of lactic acid in blood is generally less than 1.20 x 10-4 M, corresponding to the sum of [lactate] and [lactic acid]. During strenuous exercise, however, oxygen in the muscle tissue is depleted, and overproduction of lactic acid occurs. This leads to a condition known as lactic acidosis, which is characterized by elevated blood lactic acid levels (approximately 5.00 x 10-3 M). The pKa of lactic acid is 3.9. a) What is the actual lactic acid concentration under normal physiological conditions?

b) what is the actual lactic acid concentration during lactic acid acidosis?