Verified answer

Ответ:

Mr(Na3PO4) = Ar(Na)*3+Ar(P)+Ar(O)+4 = 23*3+31+16*4 = 164

Mr(Mg(NO3)2) = Ar(Mg)+Ar(N)*2+Ar(O)*6 = 24+14*2+16*6=148

Mr(BaCO3) = Ar(Ba)+Ar(C)+Ar(O)*3 = 137+12+16*3 = 197

Mr(Al2(SO4)3) = Ar(Al)*2+Ar(S)*3+Ar(O)*12 = 27*2+32*3+16*12=342