Is 2NaOH+ H2SO4 --> Na2SO4 + H2O balanced?

Answer: No, 2NaOH + H2SO4 --> Na2SO4 + H2O is not balanced.To balance ,you need place coefficient 2 before H2O.

Here is the balanced equation:

H₂SO₄ + 2NaOH--> Na₂SO₄ +2 H₂O

Reactants           Products

H--> 4                      H-->4

SO₄ --> 1               SO₄ --> 1 

Na-->2                      Na-->2

The number of hydrogen,sulphate,and sodium is equal from both sides.So H₂SO₄ + 2NaOH--> Na₂SO₄ +2 H₂O is  the balanced equation for sodium hydroxide and sulfuric acid --->sodium sulphate + water

Here is a video that will help you to understand how to balance H2SO4 + NaOH--> Na2SO4 + H2O.