A solution containing Cu(I), Ni and Zn cyanide complexes was electrolysed and a deposit of 0.175 g was obtained. The deposit contained 72.8% Cu, 4.3% Ni and 22.9% Zn. No other element was released. Calculate the number of coulombs passed through the solution.

Answer

To calculate the number of coulombs passed through the solution during the electrolysis, we will follow these steps:

### Step 1: Calculate the mass of each metal in the deposit
The total mass of the deposit is 0.175 g. We will calculate the mass of Cu, Ni, and Zn based on their percentage composition.

- Mass of Cu = 72.8% of 0.175 g
- Mass of Ni = 4.3% of 0.175 g
- Mass of Zn = 22.9% of 0.175 g

Calculating these values:
- Mass of Cu = 0.728 * 0.175 g = 0.1234 g
- Mass of Ni = 0.043 * 0.175 g = 0.007525 g
- Mass of Zn = 0.229 * 0.175 g = 0.040075 g

### Step 2: Calculate the number of moles of each metal
Using the molar masses:
- Molar mass of Cu = 63.5 g/mol
- Molar mass of Ni = 58.7 g/mol
- Molar mass of Zn = 65.4 g/mol

Calculating the number of moles:
- Moles of Cu = Mass of Cu / Molar mass of Cu = 0.1234 g / 63.5 g/mol = 0.001943 mol
- Moles of Ni = Mass of Ni / Molar mass of Ni = 0.007525 g / 58.7 g/mol = 0.000128 mol
- Moles of Zn = Mass of Zn / Molar mass of Zn = 0.040075 g / 65.4 g/mol = 0.000613 mol

### Step 3: Calculate the total charge for each metal
Now we will calculate the total charge using Faraday's laws of electrolysis. The number of electrons transferred for each metal is as follows:
- Cu (Cu^+): 1 electron
- Ni (Ni^2+): 2 electrons
- Zn (Zn^2+): 2 electrons

Calculating the total charge (Q) for each metal:
- Charge for Cu = Moles of Cu × 1 × 96500 C/mol = 0.001943 mol × 1 × 96500 C/mol = 187.4 C
- Charge for Ni = Moles of Ni × 2 × 96500 C/mol = 0.000128 mol × 2 × 96500 C/mol = 24.7 C
- Charge for Zn = Moles of Zn × 2 × 96500 C/mol = 0.000613 mol × 2 × 96500 C/mol = 118.5 C

### Step 4: Calculate the total charge passed through the solution
Now, we will sum the charges for Cu, Ni, and Zn to find the total charge passed through the solution:
Total Charge (Q_total) = Charge for Cu + Charge for Ni + Charge for Zn
Q_total = 187.4 C + 24.7 C + 118.5 C = 330.6 C

### Final Answer
The total number of coulombs passed through the solution is approximately **330.6 C**.

---