Question

What mass (in gm) of Na2 SO4 would contain the same number of total ions as present in 930 gm of Ca3 (PO4 ) 2

Answer 1

64 gm

hope it helps you ✌ friend

Answer 2

Let us Know the number and ions in Ca3 (PO4 ) 2

The molecular mass of Ca3 (PO4 ) 2 = 310a.m.u

The number of moles of substance of atomic mass  a                                                          =(No. gram in sample) / molecular mass

The number of moles in Ca3 (PO4 ) 2= 430/310= 3

now, there are 5 ions total /molecules

1mole=6.023×10²³( Avogadro's number)

∴3 mole =5×3×Na ion ·················(1)

let it X gram    ·······························(2)

now molecular mass of Na2 SO4=142a.m.u

moles=x/142

now, there are (2Na)+(1×SO4)=3 ions per molecules

∴total of 3×x/142×Na ions in Na2 SO4 samples

∴compare with equation 1

3×5×Na= 3×x/142×Na

x=142×5

x= 710 gram

∴ we need 710gm of Na2 SO4 to have same no of ion as 930gm of

Ca3 (PO4 ) 2