Question

Equal volumes of three acid solutions of pH 1,2 and 3 are mixed in a vessel. What will be the H⁺ ion concentration in the mixture?

(a) 37 x 10^-2 

(b) 10^-6 

(c) 0.111 

(d) none of these

Answer 1

(a) 3.7 x 10^-2 

pH = – log₁₀ [H⁺] 

[H⁺]  = 10^-pH 

Let the volume be x mL

V₁M₁ + V₂M₂ + V₃M₃ = VM 

x mL of 10^-1M + x mL of 10^-2M + x mL of 10^-3M 

= 3 x mL of [H⁺]  

= 3 x mL of [H⁺] 

[H⁺] = 

= 0.037 

= 3.7 x 10^-2