If pH of solution changes from 4 to 5 . then the H ₃ O ⁺ ion concentration of solution

Step-by-step solution

The pH of a solution is defined as the negative base-10 logarithm of the hydronium ion concentration: pH = - ₁₀[ H ₃ O ⁺] . Given an initial pH of 4 and a final pH of 5, the corresponding hydronium ion concentrations are [ H ₃ O ⁺]₁ = 10⁻⁴ , M and [ H ₃ O ⁺]₂ = 10⁻⁵ , M , respectively. The ratio [ H ₃ O ⁺]₂ [ H ₃ O ⁺]₁ = 10⁻⁵ 10⁻⁴ = 10⁻¹ = 1 10 shows that the hydronium ion concentration decreases by a factor of 10. Final answer: D