Answer:
b. 1 x 10⁻² M.
Step-by-step explanation:
Let's see the following formula, which represents the dissociation constant:
![[OH^-]=[H_3O^+]=1\cdot10^(-7)\text{ M}.](https://img.qammunity.org/2023/formulas/chemistry/college/cn0pxbe7chbcwfxdda11phwdgepgsbrd2q.png)
If we multiply each [OH -] and [H3O +] concentrations, we obtain:
![[OH^-][H_3O^+]=1\cdot10^(-14)\text{ M}^2.](https://img.qammunity.org/2023/formulas/chemistry/college/ps7csvn5c8lkh3z5yxtnpmzbs3d7kglaeq.png)
As we have [OH -] = 1 x 10⁻¹² M, if we solve for [H3O +] and replace the value of the concentration of [OH -] we obtain:
![[H_3O^+]=(1\cdot10^(-14)M^2)/([OH^-])=(1\cdot10^(-14)M^2)/(1\cdot10^(-12)M)=1\cdot10^(-2)M=0.01\text{ M.}](https://img.qammunity.org/2023/formulas/chemistry/college/gk7cl3bxbqaxp5zvtznjb532eu346y4fb3.png)
The [H3O +] of the solution would be b. 1 x 10⁻² M.