Question

Металлический натрий растворили в воде. К полученному раствору добавили хлорид железа (III). Выпавший осадок отфильтровали и прокалили. Твёрдый остаток растворили в соляной кислоте. Напишите уравнения четырёх описанных реакций.

Answer 1

Na + HOH → NaOH + H2↑
3NaOH + FeCl3 → Fe(OH)3↓ + 3NaCl
2Fe(OH)3 (t°)→ Fe2O3 + H2O
Fe2O3 + 6HCl → 2FeCL3 + 3H2O

Answer 2

Reaction 1: Dissolving metallic sodium in water

When metallic sodium is dissolved in water, it reacts with water to produce sodium hydroxide and hydrogen gas.

The balanced chemical equation for this reaction is:

2 Na (s) + 2 H2O (l) -> 2 NaOH (aq) + H2 (g) [[1]]

Reaction 2: Adding iron(III) chloride to the obtained solution

When iron(III) chloride is added to the sodium hydroxide solution obtained from the previous reaction, a double displacement reaction occurs, resulting in the formation of sodium chloride and iron(III) hydroxide.

The balanced chemical equation for this reaction is:

FeCl3 (aq) + 3 NaOH (aq) -> Fe(OH)3 (s) + 3 NaCl (aq) [[2]]

Reaction 3: Filtration and calcination of the precipitate

The precipitate formed in the previous reaction, iron(III) hydroxide, is filtered and then heated (calcined). Calcination is the process of heating a substance to a high temperature in the absence of air or oxygen.

The balanced chemical equation for the calcination of iron(III) hydroxide is:

2 Fe(OH)3 (s) -> Fe2O3 (s) + 3 H2O (g) [[3]]

Reaction 4: Dissolving the solid residue in hydrochloric acid

The solid residue obtained from the calcination of iron(III) hydroxide is dissolved in hydrochloric acid. This reaction results in the formation of iron(III) chloride and water.

The balanced chemical equation for this reaction is:

Fe2O3 (s) + 6 HCl (aq) -> 2 FeCl3 (aq) + 3 H2O (l) [[4]]

Please note that the above reactions are based on the given information and may not represent the complete picture.