Answer to Question #143341 in General Chemistry for Wendy

Question

what is the ph of a solution prepared by mixing 18ml of 0.277m ch3co2h? Assume that the volume of the solution is additive and that Ka=1.8*10^-5

Answer 1

for weak acid concentration of H⁺ will be:

[H⁺] = $\sqrt{(K_a *C)}$

where C is the concentration of weak acid

[H⁺] = $\sqrt{(1.8\times 10^{-5} \times 0.277)}$

so [H⁺] = 1.9 $\times$ 10^-3

where pH = -log([H⁺])

pH = 2.72