If K_a of HCN =4 10⁻¹⁰ , then the pH of 2.5 10⁻¹ molar HCN ( aq ) is

Step-by-step solution

aligned [ H ₃ O ⁺ ] & = K_a C & = 4 10⁻¹⁰ 2.5 10⁻¹ & = 10⁻¹⁰ =10⁻⁵ M pH & =- [ H ₃ O ⁺ ] pH & =- (10⁻⁵ )=5 aligned