Question

in the electrolysis of dilute CuSO4 solution using platinum electrodes,2.0A current passed for 2.50hours and deposited 5.85g of copper, calculate the relative atomic mass of copper from the experiments​

Answer 1

To calculate the relative atomic mass of copper (Cu) from the given experiment, we need to use the concept of Faraday's laws of electrolysis.

First, let's calculate the total charge (Q) passed through the circuit using the formula:

Q = I * t

Where:
Q = total charge (coulombs)
I = current (amperes)
t = time (seconds)

Given:
I = 2.0 A
t = 2.50 hours = 2.50 * 60 * 60 seconds = 9000 seconds

Q = 2.0 A * 9000 s
Q = 18000 C

Next, we need to determine the number of moles of electrons (n) involved in the electrolysis. Since copper (Cu) has a +2 charge in CuSO4, each copper ion requires 2 moles of electrons for reduction.

n = Q / (Faraday constant * charge per mole of electrons)

The Faraday constant (F) is approximately 96,485 C/mol.

n = 18000 C / (96485 C/mol * 2)
n = 0.0935 mol

Since the experiment deposited 5.85 g of copper, we can calculate the molar mass (M) of copper using the formula:

M = mass / moles

M = 5.85 g / 0.0935 mol
M = 62.6 g/mol

Therefore, the relative atomic mass of copper is approximately 62.6 g/mol