A current of 4.60 A is passed through a Pb(NO3)2 solution for 1.20 hours. How much lead is plated out of the solution?
Coulombs = amp x 1.2 hr x (60 min/hr)(60 sec/min) = estimated 20,000 C.
96,485 C will plate out 207.2/2 grams Pb(about 104 g) so
(207.2/2) x (20,000/96,485) = g Pb plated out. Remember to correct the value for C; 20000 is just an estimate.
1.25
To calculate the amount of lead plated out of the solution, we need to use Faraday's law of electrolysis.
Faraday's law states that the amount of substance deposited or liberated at an electrode is directly proportional to the quantity of electricity passed through the electrolyte.
The formula to calculate the amount of substance deposited is given by:
Amount of substance = (current × time) / (n × F)
Where:
- Current is the magnitude of the current passing through the electrolyte (in amperes, A).
- Time is the duration of the current flow (in hours, h).
- n is the number of moles of electrons exchanged during the reaction.
- F is Faraday's constant, which represents the charge of one mole of electrons (F = 96485 C/mol).
Now, let's calculate the amount of lead plated out of the solution using the given information.
Given:
Current (I) = 4.60 A
Time (t) = 1.20 hours
First, we need to determine the number of moles of electrons exchanged during the reaction. Pb(NO3)2 dissociates into Pb2+ ions, which take two electrons to be reduced to lead metal. Therefore, n (number of moles of electrons) = 2.
The value of Faraday's constant (F) is 96485 C/mol.
Using these values, we can calculate the amount of lead plated out:
Amount of lead plated out (in moles) = (current × time) / (n × F)
Substituting the given values:
Amount of lead plated out (in moles) = (4.60 A × 1.20 h) / (2 × 96485 C/mol)
Now, you can solve this equation to find the amount of lead plated out.