Question

Порошок железа растворили в разбавленной серной кислоте. В раствор добавили концентрированную перекись водорода, в результате раствор приобрёл желтоватую окраску. К образовавшемуся раствору прилили раствор сульфида калия, в результате выпал осадок. На полученный осадок подействовали разбавленным раствором соляной кислоты, при этом часть осадка растворилась. Нерастворив-шаяся часть осадка имела жёлтый цвет. Составьте уравнения четырёх описанных реакций.

Answer 1

Fe + H2SO4 = FeSO4 + H2...... 2FeSO4 +H2O2 + H2SO4 = Fe2(SO4)3 + 2H2O..... Fe2(SO4)3 + 3K2S = 2FeS + S + 3K2SO4....... FeS + 2HCl = FeCl2 + H2S

Answer 2

Reaction 1: Dissolving Iron Powder in Dilute Sulfuric Acid

When iron powder is dissolved in dilute sulfuric acid, a reaction occurs. The iron reacts with the sulfuric acid to form iron sulfate and hydrogen gas. The balanced chemical equation for this reaction is:

Fe(s) + H2SO4(aq) → FeSO4(aq) + H2(g)

Reaction 2: Adding Concentrated Hydrogen Peroxide to the Solution

When concentrated hydrogen peroxide is added to the solution, a reaction takes place. The hydrogen peroxide acts as an oxidizing agent and oxidizes the iron(II) sulfate to iron(III) sulfate. This reaction results in the solution acquiring a yellowish color. The balanced chemical equation for this reaction is:

2FeSO4(aq) + H2O2(aq) → Fe2(SO4)3(aq) + 2H2O(l)

Reaction 3: Adding Potassium Sulfide Solution to the Solution

When potassium sulfide solution is added to the solution, a precipitation reaction occurs. The sulfide ions from the potassium sulfide react with the iron(III) ions from the iron(III) sulfate to form iron(III) sulfide, which is insoluble and forms a precipitate. The balanced chemical equation for this reaction is:

Fe2(SO4)3(aq) + 3K2S(aq) → 2Fe2S3(s) + 3K2SO4(aq)

Reaction 4: Treating the Precipitate with Dilute Hydrochloric Acid

When the precipitate is treated with dilute hydrochloric acid, a reaction occurs. The acid reacts with the iron(III) sulfide, dissolving part of the precipitate. The remaining undissolved portion of the precipitate has a yellow color. The balanced chemical equation for this reaction is:

Fe2S3(s) + 6HCl(aq) → 2FeCl3(aq) + 3H2S(g)

Please note that the above reactions are based on the information provided and may not be the only possible reactions that could occur in this scenario.