Answer:
2.54*10^24 particles
Explanation:
First find the particles of Na2SO4 in one mole by looking at their numbers:
Na - 2
S - 1
O - 4
2+1+4=7 particles per mole.
Convert 85.5 g Na2SO4 into moles by dividing by molar mass (142.04g). Then multiply by Avogadro's Number (6.02*10^23). Now multiply that number by 7.
85.5g/142.04g = 0.6019 moles Na2SO4
0.6019 moles * 6.02*10^23 = 3.623*10^23
3.623*10^23 * 7 particles = 2.54*10^24 particles