A solution is 0.10 M in a weak acid HA (K_a = 4.0 x 10^-6) and 0.10 M in a weak acid HB (K_a = 1.0 x 10^-6). Use [H+] = sqrtK_a1c_1 + K_a2c_2. The pH is closest to

NEET levelSingle correct optionDifficulty 1 of 3ia093

A solution is $0.10 M$ in a weak acid $HA$ ( $K_{a} = 4.0 \times 1 0^{- 6}$ ) and $0.10 M$ in a weak acid $HB$ ( $K_{a} = 1.0 \times 1 0^{- 6}$ ). Use $[H X^{+}] = K_{a 1} c_{1} + K_{a 2} c_{2}$ . The pH is closest to

Both acids contribute:

[H X^{+}]^{2} = 4.0 \times 1 0^{- 7} + 1.0 \times 1 0^{- 7} = 5.0 \times 1 0^{- 7}

, so

[H X^{+}] = 7.1 \times 1 0^{- 4} M

and pH = 3.15.