Answer:
16.4moles
Explanation:
From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 atoms.
This clearly indicates that 1mole of (NH4)3PO4 also contains 6.02x10^23 atoms.
Now, if 1mole of (NH4)3PO4 contains 6.02x10^23 atoms,
Then Xmol of (NH4)3PO4 will contain 9.87X10^24 atoms i.e
Xmol of (NH4)3PO4 = 9.87X10^24/6.02x10^23 = 16.4moles
