The `ph` of blood stream is maintained by a proper balance of `H_(2)CO_(3)` and `NaHCO_(3)` concentrations. What volume of `5M NaHCO_(3)` solution, should be mixed with `10mL` sample of blood which is `2M` in `H_(2)CO_(3)` in order to maintain a `pH` of `7.4.K_(a)` for `H_(2)CO_(3)` in blood is `7.8 xx 10^(-7)`?

Explanation

Mixing `H_(2)CO_(3)` with `NaHCO_(3)` results in buffer solution.
`pH = pK_(a) + log[NaHCO_(3)]/[H_(2)CO_(3)] = pK_(a)+logn(NaHCO_(3))/n(H_(2)CO_(3))`
`implies 7.4 = -log(7.8 xx 10^(-7)) + log x/20 implies x = 400 m mol`
`implies NaHCO_(3) = 5 xx V implies V = 80 mL`