Final answer:
Using the provided current and time, the total charge passed through the electrode was calculated and then the number of moles of electrons was determined through Faraday's constant. Knowing that 1 mol of electrons plates 1 mol of Ag, the final mass of the silver plated was calculated to be 32.811 grams.
Step-by-step explanation:
To calculate the number of grams of silver (Ag) that can be plated onto the cathode during electrolysis, we first need to determine the total charge that has passed through the electrolysis cell. This can be calculated using the current and the time during which the current is applied.
The total charge Q is equal to the current I (in amperes) multiplied by the time t (in seconds). Given that 1 minute equals 60 seconds, our 72 minutes become 72 * 60 = 4320 seconds. Thus, with a current of 6.8 A, the total charge is:
Q = 6.8 A * 4320 s = 29376 C
Now, Faraday's constant (approximately 9.65 × 10⁴ C/mol) is used to determine the moles of electrons. One faraday corresponds to the charge on one mole of electrons, hence:
Moles of electrons = Total charge / Faraday's constant = 29376 C / (9.65 × 10⁴ C/mol) = 0.3041 mol
In the reaction for silver plating, 1 mol of electrons reduces 1 mol of Ag+ to Ag metal. Therefore, the number of moles of Ag is the same as the number of moles of electrons:
Moles of Ag = 0.3041 mol
The molar mass of silver is approximately 107.87 g/mol, so the mass of silver plated will be:
Mass of Ag = Moles of Ag * Molar mass of Ag = 0.3041 mol * 107.87 g/mol = 32.811 g