# The equation shows a neutralization reaction: H_2SO_4 + 2NaOH -> Na2SO_4 + 2H_2O. What is  Na2SO_4?

${\text{Na"_2"SO}}_{4}$ is the salt.
For a neutralization reaction, between a Brønsted-Lowry acid and a Brønsted-Lowry base, the products are always water ($\text{H"_2"O}$) and a salt.
This salt is the ionic compound formed from the cation of the base and the anion of the acid. The base here is $\text{NaOH}$, and the acid is ${\text{H"_2"SO}}_{4}$. The chemical equation shows this via exchanging the cations, just like any double-replacement reaction:
$2 \textcolor{red}{\text{Na")color(blue)("OH")(aq) + color(blue)("H"_2)color(red)("SO"_4)(aq) rarr color(red)("Na"_2"SO"_4)(aq) +2color(blue)("H"_2"O}} \left(l\right)$