Question

Calculate the [OH−] of each aqueous solution with the following [H3O+].baking soda, 1.7×10−8M

Answer 1

The [OH−] is 5.88x10^-7M.

Step-by-step explanation:

1st) It is necessary to calculate the pH of the solution using the pH formula and replacing the concentration of H3O+:

`\begin{gathered} pH=-log\left[H_3O+\right] \\ pH=-log(1.7×10−8) \\ pH=7.77 \end{gathered}`

Now we know that the pH is 7.77.

2nd) Now we can calculate the pOH of the solution using the relation between pH and pOH:

`\begin{gathered} pH+pOH=14 \\ 7.77+pOH=14 \\ pOH=14-7.77 \\ pOH=6.23 \end{gathered}`

Now we know that the pOH of the solution is 6.23.

3rd) Finally, we can calculate the [OH−] using the pOH formula and replacing the value of pOH:

`\begin{gathered} pOH=-log\left[OH−\right] \\ 6.23=-log\left[OH−\right] \\ 10^((-6.23))=\left[OH−\right] \\ 5.88*10^(-7)=\left[OH−\right] \end{gathered}`

So, the [OH−] is 5.88x10^-7M.