Question

How the Molar Concentration of H2SO4 is two times more than the normal concentration?

Answer 1

Sulphuric acid (H2SO4) is much more acidic than hydrochloric acid (HCl) of equal or same molar concentration. We can say it is twice as acidic as HCl acid.

This is because H2SO4 is a dibasic acid, and one mole of it requires two moles of a monoacidic base like NaOH (alkali) for complete neutralisation.

H2SO4 + 2NaOH = Na2SO4 + 2H2O

On the other hand, one mole HCl needs just one mole of NaOH for complete neutralisation, as it is monobasic.

HCl + NaOH = NaCl + H2O

Thus, H2SO4 can consume twice as much base (alkali) as HCl of same molar concentration consumes.

But, the H(+) ion concentration of H2SO4 will be only slightly greater than that of HCl of same molar concentration. This is because H2SO4 almost entirely exists as H(+) and HSO4(-) ions in aqueous solution (in the absence of a base); the second ionisation of HSO4(-) ion into the H(+) and the SO4(2-) ions does not occur to a considerable extent in water.

H2SO4 + H2O = H3O(+) + HSO4(-)

HCl + H2O = H3O(+) + Cl(-)

So, there won’t much difference in pH between the two acids of equal or same molar concentration.

I hope it helps