Final answer:
To determine the grams of gold plated, one should use Faraday's laws of electrolysis by calculating the total charge with the formula Q = I × t, then derive the number of moles of gold, and finally multiply by gold's molar mass, accounting for its valency.
Step-by-step explanation:
To calculate the amount of gold plated by electroplating for 25 seconds at 1.5 A, we can apply Faraday's laws of electrolysis. First, we need to find the total charge passed through the gold plating solution. The charge Q in coulombs can be found using the formula Q = I × t, where I is current in amperes and t is time in seconds.
For our scenario, Q = 1.5 A × 25 s = 37.5 C. Gold has a molar mass of approximately 197 g/mol and a valency of +3, as each gold ion (Au^3+) accepts three electrons. The faraday constant is approximately 96,485 C/mol, which is the charge required to plate or dissolve 1 mole of a substance with a valency of 1.
To find the number of moles of gold, we use the formula:
moles = (Q × valency) / (Faraday constant)
In this case:
moles = (37.5 C × 1) / (96,485 C/mol × 3)
Now, we can calculate the mass of gold plated:
mass = moles × molar mass
Using the values:
mass = moles × 197 g/mol
This will give us the mass of gold in grams that was plated in the mentioned time period. One would need to finish the calculations with the given values to get the specific number of grams of gold.