Answer:
1.25x10^24 molecules
Step-by-step explanation:
1 mole of any substance contains 6.02x10^23 molecules.
Therefore, 1mole of SO4 also contains 6.02x10^23 molecules.
1mole of SO4 = 32 + (16x4) = 32 + 64 = 96g
If 1mole( i.e 96g) of SO4 contains 6.02x10^23 molecules,
Therefore 200g of SO4 will contain = (200 x 6.02x10^23) /96
= 1.25x10^24 molecules