Question

The pH of a popular soft drink is 3.4, what is its hydronium ion concentration? a. 5.0 x 10^-4 Mb. 4.0 x 10^-4 Mc. 2.5 x 10^3 M d. 1.0 x 10^-7 Me. 5.0 x 10^-5 M

Answer 1

pH is given by the following:

$\begin{gathered} pH=-log[H_3O^+] \\ [H_3O^+]=10^{-pH} \\ [H_3O^+]=10^{-3.4} \\ [H_3O^+]=3.98\times10^{-4}M\cong4.0\times10^{-4}M \end{gathered}$

Answer: B) 4.0x10^-4M