BaCl2+H2SO4=BaSO4+2HCl
<span>FeBr2+2KOH=Fe(OH)2+2KBr</span>
<span>2 Al + 6 HCl = 2 AlCl3 + 3 H<span>2
</span></span><span>2 AlCl3 = 2 Al + 3 Cl<span>2
</span></span><span>2 Al + 3 H2S = Al2S3 + 3 H<span>2
</span></span><span>Al2S3 + 6 H2O = 2 Al(OH)3 + 3 H2S
</span><span>2 Al(OH)3 = Al2O3 + 3 H2O
</span><span>2 Al2O3 = 4 Al + 3 O<span>2</span></span>
Масса иона кислорода 2- равно 16г.