Объяснение:
Mr(Cr2(SO4)3) = 52*2+32*3+16*12=392
W(Cr) = Ar(Cr)*n / Mr(Cr2(SO4)3) *100% = 52*2 / 392 *100% =27%
W(S) = Ar(S)*n / Mr(Cr2(SO4)3) *100% = 32*3 / 392 *100% =24%
W(O)= Ar(O) *n / Mr(Cr2(SO4)3) *100% = 16*12 / 392 *100% =49%
