Calculate the ratio of HPO4(2-) to H2PO4(-) in a buffer solution at pH 7.44, given the Ka of H2PO4(-) is 6.2 x 10⁻⁸.

Here are the solutions for parts (a), (b), and (c).

The buffer system involves dihydrogen phosphate ($H_2PO_4^-$) as the acid (HA) and hydrogen phosphate ($HPO_4^{2-}$ ) as its conjugate base ($A^-$).
The equilibrium is:
$H_2PO_4^- (aq) \rightleftharpoons H^+ (aq) + HPO_4^{2-} (aq)$

Given:
pH = 7.44
$K_a = 6.2 \times 10^{-8}$

First, calculate the $pK_a$:

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