# How many moles are there in 458 grams of Na_2SO_4?

$\text{3.22 mol}$
Molar mass of $\text{Na"_2"SO"_4 = "142.04 g/mol}$
Number of moles in $\text{458 g}$ of it is$= \text{458 g"/"142.04 g/mol" = "3.22 mol}$