The net ionic equation for the reaction between aqueous sulfuric acid and aqueous sodium hydroxide is

 + 2NaOH → Na2SO4 + 2H2O

The ionic equation omits ions which act as spectators so we can split the reactants and the products into ions to see which are the spectators.

H2SO4 → 2H+ + (SO4)2-

NaOH → Na+ + (OH)-

Na2SO4 → 2Na+ + (SO4)2-

(sodium salts are generally soluble and dissociate into their ions when in solution)

H2O exists in the molecular form

So we get 2H+ + (SO4)2- + 2Na+ + 2(OH)- →2Na+ + (SO4)2- + 2H2O

We see that Na+ and (SO4)2- appears on both sides of the equation, hence they are spectators and can be removed in the ionic equation.

So we get 2H+ + 2(OH)- → 2H2O effectively as the ionic equation.

It is good practice to give the equation in the simplest number ratio and hence the net ionic equation is H+ + (OH)- → H2O

Explanation: