First, we must know this:
1 mole of anything = 6.022 x 10^23 6.022 formula units
Procedure:
We have 9.11 moles, so, we do this:
1 mole of Na2SO4 ------------ 6.022 x 10^23 6.022 formula units
9.11 moles of Na2SO4 ------------ x
[tex]x\text{ = }\frac{9.11\text{ moles x 6.022x}10^{23}formula\text{ units}}{1\text{ mole}}=\text{ }5.48\text{ x }10^{24}\text{ formula units}[/tex]Answer: 5.48x10^24 formula units
