Answer :
First convert mega grams to grams
(9.57x10^2)*(10^6)=957100000 grams
Then find the molar mass of nickel sulphate
Nickel Ni 3+ and sulphate SO4 2+
So formula= Ni2(SO4)3
So mr = (59*2) + (32*3) + (16*12)
= 406gmol-1
Moles = mass/mr
957100000/406
=2357389.163 moles