Răspuns:
A,Na=23 A,S=32 A,Mg=24 A,Cl=35,5 AFe-56 A,O=16
a. mNa:mS=2x23 :32
=23:16
b. mMg :mCl= 24 :2x35,5
24: 71
c. mFe:mS:mO= 56 :32:4X16
=7 :4 :8
1mol Na3PO4.................3mol atomiNa
4mol.......................................x= 12mol atomiNa
1molNaCl............1mol atomiNa
x................................12
x= 12molNaCl
1molNa2SO4...........2mol atomiNa
x..................................12
x= 6molNa2SO4
Explicație: