3.
Mr(SO)=32+16=48
W(S)=32/48=0.67=67%
W(O)=16/48=0.33=33%
Mr(SO2)=32+2*16=64
W(S)=32/64=0.5=50%
W(O)=32/64=0.5=50%
Mr(SO3)=32+3*16=80
W(S)=32/80=0.4=40%
W(O)=48/80=0.6=60%
<span> AL- Al2O3- Alcl3- Al(OH)3- Al2(SO4)3
</span>B2O3 + 2Al = Al2O3 + 2B
Al2O3 + 6HCl(конц. , гор. ) = 2AlCl3 + 3H2O
AlCl3 + 3H2O(гор. ) = Al(OH)3↓ + 3HCl↑
2Al(OH)3 = Al2O3 + 3H2O
<span>Al2O3 + 3K2S2O7 = Al2(SO4)3 + 3K2SO4
</span>