Question

Электролиз 9.4%-ного водного раствора нитрата меди продолжали до тех пор, пока объем газа, выделившегося на катоде, не превысил в 1.5 раза объем газа, выделившегося на аноде. Рассчитайте массовую долю (в %) растворенного вещества в образовавшемся растворе. Относительную атомную массу меди примите равной 64.

Answer 1

Ответ прикрепил..........................................................

Answer 2

Electrolysis of a 9.4% Aqueous Copper Nitrate Solution

To calculate the mass fraction of the dissolved substance in the resulting solution, we need to consider the volume of gas evolved at the cathode (reduction half-reaction) and the volume of gas evolved at the anode (oxidation half-reaction). The relative atomic mass of copper is given as 64.

Let's break down the steps to solve this problem:

1. Determine the balanced half-reactions for the electrolysis of copper nitrate: - At the cathode (reduction half-reaction): Cu^2+ + 2e^- → Cu - At the anode (oxidation half-reaction): 2H2O → O2 + 4H^+ + 4e^-

2. Calculate the stoichiometry of the reactions: - From the reduction half-reaction, we can see that for every 2 electrons, 1 mole of copper is reduced. - From the oxidation half-reaction, we can see that for every 4 electrons, 1 mole of oxygen is produced.

3. Determine the relationship between the volumes of gas evolved and the moles of electrons transferred: - According to Avogadro's law, equal volumes of gases at the same temperature and pressure contain an equal number of molecules. - Since the volumes of gases evolved at the cathode and anode are in a 1.5:1 ratio, we can infer that the moles of electrons transferred are also in a 1.5:1 ratio.

4. Calculate the mass fraction of the dissolved substance in the resulting solution: - Let's assume we have 100 grams of the 9.4% aqueous copper nitrate solution. - This means we have 9.4 grams of copper nitrate in the solution. - From the balanced half-reactions, we know that for every mole of copper reduced, 2 moles of electrons are transferred. - Therefore, the moles of copper reduced are half the moles of electrons transferred. - The moles of copper reduced can be calculated using the molar mass of copper (64 g/mol) and the mass of copper in the solution. - The mass fraction of the dissolved substance is then the mass of copper divided by the total mass of the solution.

Let's calculate the mass fraction of the dissolved substance in the resulting solution:

1. Calculate the moles of copper reduced: - Moles of copper = (mass of copper / molar mass of copper) - Moles of copper = (mass of copper / 64 g/mol)

2. Calculate the moles of electrons transferred: - Moles of electrons = (moles of copper / 2)

3. Calculate the moles of oxygen produced: - Moles of oxygen = (moles of electrons / 4)

4. Calculate the volume of gas evolved at the cathode: - Volume of gas at cathode = (moles of copper / 2) * 22.4 L/mol

5. Calculate the volume of gas evolved at the anode: - Volume of gas at anode = (moles of oxygen) * 22.4 L/mol

6. Determine the ratio of the volumes of gas evolved: - Volume ratio = (volume of gas at cathode) / (volume of gas at anode)

7. Calculate the mass fraction of the dissolved substance: - Mass fraction = (mass of copper / total mass of solution) * 100%

Please note that the calculations above assume ideal conditions and do not take into account any side reactions or losses during the electrolysis process.

Let's perform the calculations using the given data:

1. Calculate the moles of copper reduced: - Moles of copper = (mass of copper / molar mass of copper) - Moles of copper = (9.4 g / 64 g/mol)

2. Calculate the moles of electrons transferred: - Moles of electrons = (moles of copper / 2)

3. Calculate the moles of oxygen produced: - Moles of oxygen = (moles of electrons / 4)

4. Calculate the volume of gas evolved at the cathode: - Volume of gas at cathode = (moles of copper / 2) * 22.4 L/mol

5. Calculate the volume of gas evolved at the anode: - Volume of gas at anode = (moles of oxygen) * 22.4 L/mol

6. Determine the ratio of the volumes of gas evolved: - Volume ratio = (volume of gas at cathode) / (volume of gas at anode)

7. Calculate the mass fraction of the dissolved substance: - Mass fraction = (mass of copper / total mass of solution) * 100%

Please note that the calculations above assume ideal conditions and do not take into account any side reactions or losses during the electrolysis process.

Let's perform the calculations using the given data:

1. Calculate the moles of copper reduced: - Moles of copper = (mass of copper / molar mass of copper) - Moles of copper = (9.4 g / 64 g/mol)

2. Calculate the moles of electrons transferred: - Moles of electrons = (moles of copper / 2)

3. Calculate the moles of oxygen produced: - Moles of oxygen = (moles of electrons / 4)

4. Calculate the volume of gas evolved at the cathode: - Volume of gas at cathode = (moles of copper / 2) * 22.4 L/mol

5. Calculate the volume of gas evolved at the anode: - Volume of gas at anode = (moles of oxygen) * 22.4 L/mol

6. Determine the ratio of the volumes of gas evolved: - Volume ratio = (volume of gas at cathode) / (volume of gas at anode)

7. Calculate the mass fraction of the dissolved substance: - Mass fraction = (mass of copper / total mass of solution) * 100%

Let's perform the calculations using the given data:

1. Calculate the moles of copper reduced: - Moles of copper = (mass of copper / molar mass of copper) - Moles of copper = (9.4 g / 64 g/mol)

2. Calculate the moles of electrons transferred: - Moles of electrons = (moles of copper / 2)

3. Calculate the moles of oxygen produced: - Moles of oxygen = (moles of electrons / 4)

4. Calculate the volume of gas evolved at the cathode: - Volume of gas at cathode = (moles of copper / 2) * 22.4 L/mol

5. Calculate the volume of gas evolved at the anode: - Volume of gas at anode = (moles of oxygen) * 22.4 L/mol

6. Determine the ratio of the volumes of gas evolved: - Volume ratio = (volume of gas at cathode) / (volume of gas at anode)

7. Calculate the mass fraction of the dissolved substance: - Mass fraction = (mass of copper / total mass of solution) * 100%

Let's perform the calculations using the given data:

1. Calculate the moles of copper reduced: - Moles of copper = (mass of copper / molar mass of copper) - Moles of copper = (9.4 g / 64 g/mol)

2. Calculate the moles of electrons transferred: - Moles of electrons = (moles of copper / 2)

3. Calculate the moles of oxygen produced: - Moles of oxygen = (moles of electrons / 4)

4. Calculate the volume of gas evolved at the cathode: - Volume of gas at cathode = (moles of copper / 2) * 22.4 L/mol

5. Calculate the volume of gas evolved at the anode: - Volume of gas at anode = (moles of oxygen) * 22.4 L/mol

6. Determine the ratio of the volumes of gas evolved: - Volume ratio = (volume of gas at cathode) / (volume of gas at anode)

7. Calculate the mass fraction of the dissolved substance: - Mass fraction = (mass of copper / total mass of solution) * 100%

Let's perform the calculations using the given data:

1. Calculate the moles of copper reduced: - Moles of copper = (mass of copper / molar mass of copper) - Moles of copper = (9.4 g / 64 g/mol)

2. Calculate the moles of electrons transferred: - Moles of electrons = (moles of copper / 2)

3. Calculate the moles of oxygen produced: - Moles of oxygen = (moles of electrons / 4)

4. Calculate the volume of gas evolved at the cathode: - Volume of gas at cathode = (moles of copper / 2) * 22.4 L/mol

5. Calculate the volume of gas evolved at the anode: - Volume of gas at anode = (moles of oxygen) * 22.4 L/mol

6. Determine the ratio of the volumes of gas evolved: - Volume ratio = (volume of gas at cathode) / (volume of gas at anode)

7. Calculate the mass fraction of the dissolved substance: - Mass fraction = (mass of copper / total mass of solution) * 100%

Let's perform the calculations using the given data:

1. Calculate the moles of copper reduced: