Question

NaOH + H2SO4 -> H2O + NaHSO4. The net ionic equation for this molecular equation was H+ + OH- = H2, meaning that H2SO4 needed to break up into H+ and HSO4-. I thought that H2SO4 breaks up into 2H+ and SO42-... Why does it break up like H+ and HSO4-?? (There were no moles of acid/base told on the question..)

Answer 1

Based on the scenario, the reason why it break up is because the H2 isn't bonded to one element

H ions can only be broken up one at a time unless it's bonded to one element

hope this helps

Answer 2

Answer: It is because of an insufficient supply of NaOH needed for the complete reaction with the diprotic acid H2SO4.

Explanation

Neutralization reaction is the reaction between an acid and a base or alkalis to yield salt and water.

Monoprotic acids like HCl ionizes only in one step $HCl = H+ + Cl-$

Diprotic acids ( with two protons or hydrogen ions per molecule ) like H2SO4 ionizes in a stepwise manner by losing one proton at a time

$H2SO4 = H+ + HSO4-$

$HSO4- = H+ + SO42-$

Also, a salt is formed when all or part of the ionizable hydrogen of an acid is replaced by a metal or ammonium ion.

Monoprotic acids can only form one type of salt – normal salts

$NaOH + HCl = NaCl + H2O$

Diprotic acid can form two types of salts – normal salts and acid salts.

$NaOH + H2SO4 = NaHSO4 + H2O$

$2NaOH + H2SO4 = Na2SO4 + 2H2O$

The product of the first equation NaHSO4 (acid salt) was formed as a result of the insufficient supply of NaOH hence the hydrogen ions of H2SO4 were partially replaced while in the second equation Na2SO4 (normal salt) was formed because 2 moles of NaOH was used in the reaction and that was enough to completely neutralize the diprotic acid H2SO4.