) When a current of 0.75A is passed through a CuSO4 solution for 25 min, 0.369 g of copper is deposited at the cathode. Calculate the atomic mass of copper.

To determine the atomic mass of copper based on the given information, we can use Faraday's laws of electrolysis. The process involves calculating the amount of charge that has passed through the solution and relating it to the mass of copper deposited. Let's break this down step by step.

Step 1: Calculate Total Charge (Q)

The total charge can be calculated using the formula:

Q = I × t

Where:

• Q is the total charge in coulombs (C)
• I is the current in amperes (A)
• t is the time in seconds (s)

Given:

• Current, I = 0.75 A
• Time, t = 25 minutes = 25 × 60 = 1500 seconds

Now, substituting the values:

Q = 0.75 A × 1500 s = 1125 C

Step 2: Calculate Moles of Copper Deposited

According to Faraday's laws, the amount of substance deposited at an electrode is directly proportional to the total charge passed through the electrolyte. The relationship can be expressed as:

m = (Q × M) / (n × F)

Where:

• m is the mass of the substance deposited (in grams)
• M is the molar mass (or atomic mass) of the substance (in g/mol)
• n is the number of electrons transferred per atom of the substance
• F is Faraday's constant (approximately 96485 C/mol)

For copper (Cu), the number of electrons transferred (n) during the reduction process is 2 (Cu²⁺ + 2e⁻ → Cu). We can rearrange the formula to solve for M:

M = (m × n × F) / Q

Step 3: Substitute Values and Calculate

We know:

• m = 0.369 g
• n = 2
• F = 96485 C/mol
• Q = 1125 C

Now, substituting these values into the formula:

M = (0.369 g × 2 × 96485 C/mol) / 1125 C

Calculating this gives:

M = (0.369 × 2 × 96485) / 1125 ≈ 61.5 g/mol

Final Result

The calculated atomic mass of copper based on the electrolysis experiment is approximately 61.5 g/mol. However, the accepted atomic mass of copper is about 63.55 g/mol. The discrepancy can arise from experimental errors or assumptions made during calculations, such as purity of the copper sulfate solution or efficiency of the electrolysis process.