Ответ:

BaSO4 233

K2CO3 138

H2SO4 98

Fe(OH)3 107

Al2(SO4)3 342

Ответ:

Mr(BaSO4) = Ar(Ba)+Ar(S)+Ar(O)*4 = 137+32+16*4 = 233

Mr(K2CO3) = Ar(K)*2+Ar(C)+Ar(O)*3 = 39*2+12+16*3 = 138

Mr(H2SO4) = Ar(H)*2+Ar(S)+Ar(O)*4 = 1*2+32+16*4 = 98

Mr(Fe(OH)3) = Ar(Fe)+Ar(O)*3+Ar(H)*3 = 56+16*3+1*3 = 107

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