Question

Решите пожалуйстаПри электролизе водного раствора сульфата меди (II) образовался металл. Металл растворили в концентрированной азотной кислоте. Образовавшуюся в результате соль выделили и прокалили. Полученный твёрдый остаток обработали соляной кислотой. Напишите уравнения четырёх описанных реакций.

Answer 1

CuSO4 --(электролиз)--> Cu + O2 + H2SO4
Cu + 4HNO3(конц.) --> Cu(NO3)2 + 2NO2 + 2H2O
2Cu(NO3)2 --(t)--> 2CuO + 4NO2 + O2
CuO + 2HCl --> CuCl2 + H2O

Answer 2

Electrolysis of Copper(II) Sulfate Solution

When a solution of copper(II) sulfate (CuSO4) is electrolyzed, several reactions occur. The positive copper ions (Cu2+) are attracted to the negative electrode (cathode) and are reduced to metallic copper (Cu) through the gain of electrons. At the same time, water molecules at the positive electrode (anode) are oxidized, producing oxygen gas (O2) and hydrogen ions (H+). The overall reaction can be represented as follows:

Cathode reaction: Cu2+(aq) + 2e- → Cu(s) Anode reaction: 2H2O(l) → O2(g) + 4H+(aq) + 4e-

Dissolving the Copper Metal in Concentrated Nitric Acid

The metallic copper obtained from the electrolysis is then dissolved in concentrated nitric acid (HNO3). Nitric acid is a strong oxidizing agent and reacts with copper to form copper(II) nitrate (Cu(NO3)2), nitrogen dioxide gas (NO2), and water. The reaction can be represented as follows:

Cu(s) + 4HNO3(aq) → Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l)

Precipitation and Calcination of the Copper Nitrate

The copper nitrate solution obtained from the previous step is then subjected to precipitation and calcination. Precipitation involves adding a suitable reagent to the solution to form a solid precipitate, while calcination involves heating the precipitate to obtain the desired product.

In this case, the copper nitrate solution is treated with a reagent that forms an insoluble copper compound. One possible reagent is sodium hydroxide (NaOH), which reacts with copper nitrate to form copper(II) hydroxide (Cu(OH)2) as a precipitate:

Cu(NO3)2(aq) + 2NaOH(aq) → Cu(OH)2(s) + 2NaNO3(aq)

The precipitate of copper(II) hydroxide is then heated (calcined) to convert it into copper(II) oxide (CuO):

Cu(OH)2(s) → CuO(s) + H2O(g)

Treatment of the Copper Oxide with Hydrochloric Acid

The copper oxide obtained from the previous step is treated with hydrochloric acid (HCl). Copper oxide reacts with hydrochloric acid to form copper(II) chloride (CuCl2) and water:

CuO(s) + 2HCl(aq) → CuCl2(aq) + H2O(l)

These are the four reactions involved in the given sequence of steps.