Electrochemistry II. Electrolsis

In summary, the question is asking for the mass of copper that could be electroplated on the cathode in an experiment where an average of 200 mA was passed through the cell for 35 mins. To find this, we need to calculate the total charge transferred, Q = I*t, and then use the reduction reaction equation Cu2+(aq) + 2e ------> Cu(s) to determine the number of moles of Cu deposited. Finally, we can use the molar mass of Cu (63.55 g/mol) to calculate the mass of copper that could be electroplated on the cathode. However, without further information about the electrolyte used, we cannot accurately determine the mass of copper.
  • #1
david2120
15
0
what mass of copper could be electroplated on the cathode in an experiment where an average of 200 mA was passed through the cell for 35 mins?

I don't understand the question? how do you figure the mass out? I know that copper is 63.55g/mole but do i mutiple it by 200mA and 35 mins?
 
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  • #2
You can figure out the total charge that reaches the cathode, and from there consider the reduction reaction.
 
  • #3
200mA x 2100secs divide 1000mA = 420 coulombs

I am doing in right so far and what do I do next? How do I find what mass of copper could be electroplated on the cathode?
 
  • #4
Again, we have an incomplete question. Is there no reference to the electrolyte used ? The answer will vary depending on whether the electrolyte has Cu+ ions or Cu2+ ions. In the absence of further information, assume it's Cu2+ and proceed.

What you've done is correct so far. Now, what is the purpose of transfering this charge - what does it do to the ions in the electrolyte ?
 
  • #5
2 moles of electrons to produce one mole of copper because the equation is Cu2+(aq) + 2e ------> Cu(s) i know Cu is 63.55g/mole but that's all the info I have
 
  • #6
david2120 said:
2 moles of electrons to produce one mole of copper because the equation is Cu2+(aq) + 2e ------> Cu(s) i know Cu is 63.55g/mole but that's all the info I have
Was the equation given to you as part of the question ?
 
  • #7
no I got it from the experiment we did in trying to determine Faraday's constant the question is a postlab question. I weighted the copper strips which was 16.57 and 19.051 and lowered to 16.563 and 19.014 after the experiment was done but I don't know am supposed to use those numbers cause the average current i got was 9.0745x10^-2 and in the post question it says average of 200 mA
 
  • #8
I'm going to ignore the numbers you got in your lab and help you only with the postlab question. But henceforth, please provide all the information that comes with the question.

So far, you've got the total charge, Q = I*t (in Coulombs)

Do you see a way of going from the total charge transferred to the number of moles of Cu deposited ? Remember, it takes two moles of electrons to deposit one mole of Cu.
 

1. What is the purpose of electrolysis in electrochemistry?

Electrolysis is a process in which electrical energy is used to bring about a chemical reaction. In electrochemistry, it is used to convert electrical energy into chemical energy, and it is often used to produce or purify metals.

2. How does electrolysis work?

Electrolysis involves the use of an external source of direct electric current to drive a non-spontaneous chemical reaction. The current is passed through an electrolyte, which is a solution or molten substance that contains ions, causing the ions to migrate and undergo a chemical reaction.

3. What is the difference between electrolytic and galvanic cells?

In an electrolytic cell, electrical energy is used to drive a non-spontaneous chemical reaction, whereas in a galvanic cell, a spontaneous chemical reaction produces electrical energy. Electrolytic cells have a negative standard cell potential, while galvanic cells have a positive standard cell potential.

4. What factors affect the rate of electrolysis?

The rate of electrolysis is affected by several factors including the current, the concentration of the electrolyte, the surface area of the electrodes, the distance between the electrodes, and the temperature. Higher currents, concentrations, and temperatures generally increase the rate of electrolysis, while larger surface areas and shorter distances between electrodes also increase the rate.

5. What are some practical applications of electrolysis?

Electrolysis has many practical applications, such as in the production of metals, such as aluminum and copper. It is also used in the purification of metals, such as gold and silver. Electrolysis is also used in the production of chlorine and other industrial chemicals. Additionally, it is used in the production of hydrogen for fuel cells and in the extraction of rare earth metals for use in electronics.

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