Question

BaCO3-->BaO-->Ba(OH)2-->Ba3(PO4)2-->BaCl2

Answer 1

BaCO3(t)=BaO+CO2
BaO+H2O=Ba(OH)2
39Ba(OH)2+2Na3PO4=Ba3(PO4)2+6NaOH
Ba3(PO4)2+3CaCl2=3BaCl2+Ca3(PO4)2