The mass of Nickel(II) phosphate = 5508.646 g
Further explanation
Given
9.06 x 10²⁴ of Nickel(II) phosphate
Required
The mass
Solution
1 mol = 6.02 x 10²³ particles(molecules,ions, atoms)⇒Avogadro's number
So mol Nickel(II) phosphate :
n = N : No
n = 9.06 x 10²⁴ : 6.02 x 10²³
n = 15.05
mass of Nickel(II) phosphate(Ni₃(PO₄)₂ , MW=366.023 g/mol) :
mass = mol x MW
mass = 15.05 x 366.023
mass = 5508.646 g