М(NaCl) =23+ 35 = 58
M(CaCl2) = 40 + 35*2=110
M(CaO) = 40 + 16=56
M(NCl) = 14 + 35=49
M(Fe(OH)3 = 56+16*3 + 1*3 =107
M(H2SO4 = 1*2 + 32+16*4 = 98
M( Na3PO4 = 23*3 + 31 + 16*4 = 164
M(KNO3 = 39+14 + 16*3 = 101
M(NaOH) = 23 +16 +1= 40
M(P2O5) = 31 *2 + 16*5 = 142