Question

a mixture of solution was made taking 0.1(M) of hydrochloric acid and 0.1(M) of sulfuric acid,2ml each.and then pour it in 6ml of 0.4(M) sodium chloride solution.what will be the PH of the solution?

Answer 1

Buffer is composed of a weak acid and its conjugate base, or a weak base and its conjugate acid, but since HCl and $\mathrm{H}_2\mathrm{SO}_4$ are strong acids - they would not make a buffer solution.

pH for this mixture is equal to $-\log[\mathrm{H}^+]$, concentration of $[\mathrm{H}^+]$ is equal to $[\mathrm{HCl}] + 2[\mathrm{H}_2\mathrm{SO}_4]$ (because last one is strong diprotic acid), so

$$[\mathrm{H}^+] = 0.1 + 2 \cdot 0.1 = 0.3\,\mathrm{M}$$ $$\mathrm{pH} = -\log(0.3) = 0.52$$