Calculate the change in mass of the In electrode after the cell supplies 100 mA of current for 10 minutes. The balanced redox reaction is 2In+Cl2=2In+ + 2Cl-.
I understand the idea behind the question, I just don't know if I should use 1 mol In per 1 mol e- or 1 mol In per 2 mol e- when doing the calculations.
If your equation is right use 2 mol e. However, I'm somewhat surprised In doesn't go to In^3+.
To calculate the change in mass of the In electrode, we need to determine the number of electrons consumed during the supply of 100 mA of current for 10 minutes.
First, let's determine the number of moles of electrons using Faraday's law:
1. Identify the current, which is given as 100 mA. Convert this to amperes by dividing by 1000: 100 mA / 1000 = 0.1 A.
2. Convert the time to seconds. There are 60 seconds in a minute, so 10 minutes * 60 seconds/minute = 600 seconds.
3. The charge (Q) is given by the current multiplied by time: Q = 0.1 A * 600 s = 60 C (coulombs).
4. Since 1 mole of electrons carries a charge of 96485 C (Faraday's constant), we can calculate the number of moles of electrons by dividing the charge by the Faraday's constant: 60 C / 96485 C/mol = 0.0006214 mol e-.
Now we need to determine the stoichiometry of the reaction to find the change in the number of moles of In.
The balanced redox reaction equation is: 2In + Cl2 → 2In+ + 2Cl-
From the equation, we can see that 2 moles of In gain 2 moles of electrons, so the stoichiometry is 1 mole of In for 1 mole of electrons.
Therefore, we should use 1 mol In per 1 mol e- when doing the calculations.
Now, we can calculate the change in mass of the In electrode:
Since 1 mole of electrons corresponds to 1 mole of In, and the molar mass of In is known (let's assume it is M In), the change in mass (Δm) can be calculated using the formula:
Δm = (0.0006214 mol)(M In)
You will need to look up the molar mass of In to substitute into the equation above. Once you have the molar mass, you can find the change in mass of the In electrode.