Electrolytic cells shipwrecks practical help!! (1 Viewer)

[enigma_1]

Help!! Our school prac equipment doesn't help so it would be cool if you guys can tell me what exactly is going on here

I;m finding the effect that the concentration of electrolyte has on the rate of electrolysis in an electrolytic cell. I'm using copper electrode and copper sulfate solution.

When the anode and cathode electrodes are weighed at the beginning and after the experiment...

What is the change in mass for the anode? (This would tell you how much solid has been deposited from the copper sulphate solution) Please specify if the mass of anode increases (there is copper deposit) or decreases (the electrode has been oxidised into solution)

What is the change in mass for the cathode? Same idea


THAnkss so much!!! Crappy school equipment to blame

 

[strawberrye]

Difficult to answer this question because it actually depends on the purity of your electrodes...and unfortunately, when we did this prac, I didn't do this experiment with copper electrode and copper sulphate-although quantitative data provides an accurate indication of the effect of concentration of electrolyte on rate of electrolysis, but visual indications such as increase rate of efferverscence/bubbles produced-again, depend on the electrodes you used-would be equally valid in serving as evidence of increase concentration-increase rate

You don't necessary need accurate masses-definitive, as long as your data shows the general trend that higher concentration, greater mass difference-then it is fine-if your data does not show that-then now is the time to justify sources of error/accuracy/validity/reliability/ways to improve this experiment in your discussion-remember, no experiment is ever perfect and actually, rarely any experiments I have done in the sciences actually matches theoretical results-remember, being able to explain reasoning of disparities will be a key skill required in both first hand investigations and your actual written exam-hope this helps

 

[anomalousdecay]

You have a copper electrode. What is the other electrode? Is it inert? If so, you need to have a reactant.

This calculation involves the basic work of molar ratios which you would have done in preliminary.

You write the balanced equation of the redox reaction and calculate the moles of the anode which have dissolved into solution by weighing out on an electronic balance. Then you find out how many moles of the cathode were used (if this uses an inert cathode) or the deposit and calculate that. To check your answer, weigh the difference in the deposit on the cathode (If NOT inert). This can be done the other way around (vice-versa).

 

[enigma_1]

Omg thanks so much you have saved my life!!! Can you give me an example of this moles business? Yep the other electrode is inert too.

But how can I use stoichiometry, cause I only used 2 copper inert electrodes... there is no redox reaction? or is there?