Question

P -> P2O -> H3PO4 -> Ca3(PO4)2

Li -> Li2O -> LiOH -> Li2So4 

Answer 1

P -> P2O -> H3PO4 -> Ca3(PO4)2

1) 4P+10O2=2P2O5

2) P2O5+3H2O=2H3PO4

3) 2H3PO4+3CaCl2=Ca3(PO4)2+6HCl 

 Li -> Li2O -> LiOH -> Li2So4 

1)4Li+O2=2Li2O 

2) Li2O+Na(OH)2=2LiOH+NaO 

3) 2LiOH+H2SO4=Li2SO4+2H2O