Acidic buffer solution is prepared by mixing a weak acid and its salt with a strong base.Thus, a mixture of \\\\(H_{2}CO_{3}\\\\) and \\\\(HCO_{3}^{-} \\\\) acts as an acidic buffer solution.The expression for the pH of the acidic buffer solution is as given below:\\\\(pH=pK_a+log \\frac {[salt]} {[acid]}\\\\)In the presence of \\\\(NaHCO_{3}\\\\), the concentration of salt increases. Hence, the term \\\\(log \\frac {[salt]} {[acid]}\\\\) increases. This increases the \\\\(pH\\\\) of blood.