Mr(K2SO3) = 39*2 + 32 + 16*3 = 158
Mr(P2O5)=31*2 + 16*5 = 142
Mr(Fe2O3) = 56*2 + 16*3 = 160
Mr(Ba(OH)2)=137+16*2 + 1*2 = 171
Mr(Ca3(PO4)2 = 40*3 + 31*2 + 16*8 = 310
Mr(HCl) = 1+35,5 = 36,5
Mr(AgNO3) = 108 + 14 + 16*3 = 170
Mr(Ba(NO3)2 = 137 + 14*2 + 16*6 = 261
Mr(K2S) = 39*2 + 32 = 110
Mr(HNO3) = 1+14 + 16*3 = 63