Question

How to calculate pH of mixture of two strong acids?

Answer 1

If V₁ volume of a strong acid solution of normality N₁ is mixed with V₂ volume of another strong acid solution of normality N₂, then 

Number of H⁺ ions from I-solution = N₁ V₁ 

Number of H⁺ ions from II-solution = N₂V₂ 

If final normality is N and final volume is V, then 

NV = N₁V₁ + N₂V₂ 

[dissociation equilibrium of none of these acids will be disturbed as both are strong acid]