Question

The concentration of hydroxide ion in a water sample is found to be 2.5 × 10⁻⁶ M. Identify the nature of the solution.

Answer 1

The concentration of OH ion in a water sample is found to be 2.5 × 10⁻⁶ M

pOH = – log₁₀ [OH^–]

pOH = – log₁₀ [2.5 × 10⁻⁶]

= – log₁₀ [2.5] – log₁₀ [10⁻⁶]

= – 0.3979 – (– 6)

= – 0.3979 + 6

pOH = 5.6

We know that,

pH + pOH = 14

pH + 5.6 = 14

pH = 14 – 5.6

pH = 8.4

pH = 8.4, shows the nature of the solution is basic.