Question

If ion concentration of a solution increases, then its pH value .

• A. $H_3{O}^{+}$
• B. decreases
• C. remains same
• D. $O{H}^{-}$

Answer 1

Answer: (A), (B)

decreases

The pH of a solution is calculated as-
pH = $\frac{1}{\left[H^{+}\right(aq\left)\right]}$
As the concentration of $\left[H^{+}\right(aq\left)\right]$ or $H_3{O}^{+}$ ions increases the pH decreases.

In other words, higher concentration of $\left[H^{+}\right(aq\left)\right]$ ions means more acidic solution, or lower pH.