DCI 6.3 – Electrolysis
Electrolysis Simulation
Observations from the BCE 6.3
Describe the change in amount of metal on each electrode. How are these
changes related?
What flows from the + electrode in the external circuit via the wire?
What causes the direction of the flow?
What flows from the + electrode in the solution?
What is the mechanism/process that transfers the amount of metal from one
electrode to the other?
Describe the action that causes the metal ions to plate on to the – electrode.
Write a chemical equation that summarizes your explanation.
Describe the action that causes the metal ions to plate on to the + electrode.
Write a chemical equation that summarizes your explanation.
Summarize the BCE Experiments
What metals were used in the experiment you
set up in the BCE?
What variables effect the change in the amount
of metal plated on the negative electrode?
How did these variables effect the change?
Data From BCE 6.3
Current Time
(amps) (sec)
Ag (107.87 g
Zn (65.38 g mol-1) Fe (55.85 g mol-1) mol-1)
3 amp
600
0.60 g
0.52 g
2.01g
3 amp
300
0.31 g
0.26 g
1.00 g
2 amp
600
0.41 g
0.35 g
1.34 g
How does the amount in grams of the metal depend
on current and time?
Proportionalities
Time vs. Amount:
Current vs. Amount:
Amount
Observe the particulate level representation at the
cathode and the anode for the silver/silver and
the iron/iron system. Electrolysis Simulation
How are the animations the same and different?
Data From BCE 6.3
Current Time
(amps) (sec)
Zn (65.38 g mol-1)
Fe (55.85 g mol- Ag (107.87 g mol1)
1)
3 amp
600
0.00933 mol
0.00931 mol
0.0186 mol
3 amp
300
0.00459 mol
0.00466 mol
0.00927 mol
2 amp
600
0.00627 mol
0.00627 mol
0.0124 mol
Proportionalities
What is the new proportionality equation that
represents the relationships between amount, the
number of electrons transferred, time and current?
Proportionalities
amount α (current * time)/charge
To make this an equality find the value of the
proportionality constant?
Proportionalities
Time vs. Amount (moles): time α moles
Current vs. Amount (moles) : current(amps) α moles
Charge vs. Amount (moles) : 1/charge(n
electrons/ion) α moles
Summary Page
Write the summary mathematical equation a couple
of different ways.
Moles = amps*seconds/(96,500 amp-sec/mol e-)*the
number of e- transferred
Clicker Questions
• CQ1
• CQ2
Application/Clicker Question
What current (in units of amps) is required to plate
out 1.22 g of nickel from a solution of Ni2+ in 1.00
hour?
A) 65.4 B) 4.01 x 103 C) 1.11
D) 12.0 E) 2.34
Clicker Question
How many minutes will it take to plate out 2.19 g of
chromium metal from a solution of Cr3+ using a
current of 35.2 amps in an electrolyte cell?
A) 1.92 x 103 B) 5.77 C) 17.3 D) 115
E) 346
Variables
Fe (55.85)
Zn (65.37)
Ag (107.87)
3 amp/10 min
0.00931 mol
0.00933 mol
0.0186 mol
3 amp/5 min
0.00466 mol
0.00459 mol
0.00927 mol
2 amp/10 min
0.00627 mol
0.00627 mol
0.0124 mol
Fe (55.85)
Zn (65.37)
Ag (107.87)
3 amp/10 min
1
2
3
3 amp/5 min
4
5
6
2 amp/10 min
7
8
9
Time
1 vs 4
2 vs 5
3 vs 6
Current
1 vs 7
2 vs 8
3 vs 9
Amount
1 vs 2
4 vs 5
7 vs 8
1/2 vs 3
4/5 vs 6
7/8 vs 9
Charge
Proportionalities
Time vs. Amount: amount(mols) α time(sec)
Current vs. Amount: amount(mols) α
current(amps)
Current vs. Charge: amount(mols) α 1/charge(n
electrons/ion)
mols = C x amp x sec/n, C = mols n/amp-sec