Mr( Li2CO3) = 2× Ar (Li)+ 1× Ar(C) + 3× Ar ( O)= 2×6+12+3×16= 72
Mr ( KNO) = 39+14+16= 69
Mr ( Na3PO4) = 3×23+31+4×16= 164
Mr( CaO)= 40+16= 56
Mr( K2CO3)= 2×39+12+2×16= 122
Mr ( Al2(SO4)3) = 2×27+3(32+4×16)= 342
Mr( Li2CO3) = 2× Ar (Li)+ 1× Ar(C) + 3× Ar ( O)= 2×6+12+3×16= 72
Mr ( KNO) = 39+14+16= 69
Mr ( Na3PO4) = 3×23+31+4×16= 164
Mr( CaO)= 40+16= 56
Mr( K2CO3)= 2×39+12+2×16= 122
Mr ( Al2(SO4)3) = 2×27+3(32+4×16)= 342