The hydrogen ion molarity : 6.918 x 10⁻¹¹ M
pH is the degree of acidity of a solution that depends on the concentration of H⁺ ions. The greater the value the more acidic the solution and the smaller the pH.
pH = - log [H⁺]
So that the two quantities between pH and [H⁺] are inversely proportional because they are associated with negative values.
A solution whose value is different by n has a difference in the concentration of H⁺ ion of 10ⁿ.
pH of solution = 10.16
the [H₃0⁺] of the solution :
[tex]\tt pH=-log[H_3O^+]\\\\10.16=-log[H_3O^+]\\\\(H_3O^+]=10^{-10.16}=6.918\times 10^{-11}[/tex]