Answer:
number of moles of NaSO4 = [tex]\frac{mass of compound}{molar mass of compound}[/tex]
= [tex]\frac{35.9}{2(23) + 32 + 4(16)}[/tex]
= 0.253 mol (3 s.f.)
0.253 mol = [tex]\frac{number of atoms}{avogadro's number}[/tex]
= [tex]\frac{number of atoms}{6.02(10^{23} )}[/tex]
thus, the number of atoms = 0.253 x [tex]6.02(10^{23})[/tex]
= 1.52 × [tex]10^{23}[/tex]
