A current of 3.40 A is passed through a Ni(NO3)2 solution for 1.80 hours. How much nickel is plated out of the solution?
This has been posted numerous times today. See those answers.
To determine the amount of nickel plated out of the solution, you need to use Faraday's Law of Electrolysis. This law states that the mass of a substance deposited or liberated at an electrode is directly proportional to the quantity of electricity passed through the solution.
Here are the steps to calculate the amount of nickel plated:
1. Determine the charge (Q) passing through the solution.
Q = Current (I) × Time (t)
Q = 3.40 A × 1.80 hours
2. Convert the time from hours to seconds (since the SI unit for current is in amperes and time is in seconds).
t (in seconds) = 1.80 hours × 3600 seconds/hour
3. Calculate the charge in Coulombs.
Q = 3.40 A × (1.80 hours × 3600 seconds/hour)
4. Calculate the number of moles of electrons (n) involved in the reaction, using Faraday's Constant (F).
F is approximately 96,485 C/mol.
n = Q / F
5. Determine the molar ratio between nickel (Ni) and the number of moles of electrons (n).
The balanced equation for the reduction of Ni2+ ions is:
2e- + Ni2+ → Ni
The molar ratio is 1 mole of Ni for every 2 moles of electrons (2e-).
6. Calculate the moles of nickel (Ni) plated out.
Moles of Ni = n / 2
7. Determine the molar mass of nickel (Ni) from the periodic table.
8. Calculate the mass of nickel (Ni) plated out using the moles of nickel (Ni) and its molar mass.
By following these steps, you can calculate the mass of nickel plated out of the solution.