Electroplating Experiment: Calculating Copper Mass from Silver Deposition

[dav1d]

Homework Statement

Exactly 21.6 g of silver is deposited during an
electroplating experiment. The same amount of
electricity is passed through 1.00 L of a 1.00 mol/L
CuSO4(aq) solution. What mass of copper is
deposited?
Relative atomic masses:
Ag 107.87; Cu 63.55

Homework Equations

The Attempt at a Solution

I really have no idea how to do this.

 

[Borek]

Do you know Faraday's law of electrolysis?

 

[dav1d]

No, never heard of it. Can you link me to it?

 

[Borek]

http://lmgtfy.com/?q=Faraday's+law+of+electrolysis

 

[dav1d]

m=(Q/F)(M/z)

m is the mass of the substance liberated at an electrode in grams
Q is the total electric charge passed through the substance
F = 96,485 C mol−1 is the Faraday constant
M is the molar mass of the substance
z is the valency number of ions of the substance (electrons transferred per ion).


so

Q:how do i find the total charge? Only given The same amount of
electricity is passed
F=const
M: 63.55
z=1 or 2?

 

[Borek]

What reactions are taking place during electrodeposition of both metals? What is z?

Come on, show some effort, so far you are just asking for help on each step. We can help, we can't spoonfeed you.

 

[dav1d]

I just don't really understand.

Redox is happening during the electrodeposition? Z is the valence number but copper is multivalent so it can be 1 or 2?

wait

Can't you just rearrange the equation for Q, plug in the 21.6 grams from aluminum and then find the Q?
Then redo the equation with Q solved for and then plugin everything else, F=const, M=unkown, and then Z still is 1 or 2?

 

[Borek]

No idea where did you got aluminum from. But yes, you have to find the charge from known amount of reduced silver.

You are specifically told to use CuSO₄, what is the valence of the copper in this compound?

 

[dav1d]

Exactly 21.6 g of silver is deposited during an
electroplating experiment. The same amount of
electricity is passed through 1.00 L of a 1.00 mol/L
CuSO4(aq) solution.

It should be 2+ for the Cu correct?

 

[Borek]

It should be 2+ for the Cu correct?

Yes.