решить цепочку по действиям
SO2<---H2S<----S----->FeS------>H2S------>Na2S----->CuS
H2S" alt="S + H2 ---> H2S" align="absmiddle" class="latex-formula"> 2H2O + 2SO2" alt="2H2S + 3O2 ----> 2H2O + 2SO2" align="absmiddle" class="latex-formula"> FeS" alt="Fe + S ---> FeS" align="absmiddle" class="latex-formula"> FeCl2 + H2S" alt="FeS + 2HCl ---> FeCl2 + H2S" align="absmiddle" class="latex-formula"> Na2S + H2O" alt="H2S + Na2O ---> Na2S + H2O" align="absmiddle" class="latex-formula"> 2NaCl + FeS" alt="Na2S + FeCl2 ---> 2NaCl + FeS" align="absmiddle" class="latex-formula">