Sulfuric acid is a strong acid with the formula `H_2 S O_4.` Sodium carbonate is a salt of weak carbonic acid `H_2 C O_3` and its formula is `Na_2 C O_3.`
Usually when a strong acid reacts with a salt of a weak acid, the salt of the strong acid and the weak acid occur. In this problem the reaction satisfies this rule, and sodium sulphate `Na_2 S O_4` and carbonic acid are formed. Also carbonic acid is unstable and forms water `H_2 O` and carbon dioxide `C O_2` which goes out as a gas.
So the (potentially unbalanced) reaction is
`H_2 S O_4 +Na_2 C O_3 = Na_2 S O_4 +H_2 O +C O_2.`
When we examine this equation with respect to all chemical elements involved, it appears to be balanced.