All Questions
13
questions
4
votes
1
answer
95
views
Why is my Ni or Fe cathode blackening and pores getting blocked during alkaline (6 M KOH) electrolysis?
I am conducting an electrolysis process for hydrogen $(\ce{H2})$ and oxygen $(\ce{O2})$ generation using a $\pu{6 M}$ $\ce{KOH}$ alkaline solution.
During the process, I have observed that my cathode ...
13
votes
3
answers
2k
views
Do electrons really hang around the electrode while ions go take a swim?
This answer to this post addresses "what happens if you dip a single zinc electrode into some electrolyte solution." It explains that
However, though the zinc ion can diffuse through the ...
3
votes
2
answers
844
views
Disproportionation of silver(I) in aqueous solution
Use the following equations to predict whether or not $\ce{Ag+}$ ions will disproportionate in solution:
$$
\begin{align}
\ce{Ag+(aq) + e- &-> Ag} &\qquad E^\circ = \pu{+0.80 V}\\
\ce{Ag^2+(...
1
vote
1
answer
769
views
Calculating the biological standard potential
I have an electrochemical cell with following overall reaction:
$$\ce{5 Sn^4+ + 2 Mn^2+ + 8 H2O <=> 5 Sn^2+ + 2 MnO4- + 16 H+}$$
I have defined the half reactions as:
$$
\begin{align}
\ce{Sn^...
2
votes
0
answers
408
views
Effect of charge density on electrolysis of dilute sulphuric acid
I am told that if electrolysis of dilute sulfuric acid is performed under high charge density, then the following reaction takes place at anode instead of evolving oxygen:
$$\ce{2 HSO4- -> H2S2O8 +...
2
votes
0
answers
150
views
Competing half reactions in electrolysis of aqueous solution of sodium hydroxide
If you run a direct current using pure nickel electrodes through a solution of NaOH in distilled water, you will separate the water into hydrogen and oxygen.
Are there any other reactions that could ...
0
votes
1
answer
165
views
How to know which reduction and oxidation reactions occurred?
We just had a lab experiment on galvanic cells and we used 0.5 M and 1 M iron(III) nitrate solution at the anode (iron electrode) and 1 M and 0.5 M copper(II) nitrate solution at the cathode (copper ...
0
votes
1
answer
466
views
Molar conductivity of transition metal complexes solutions [closed]
Which of the following has the highest molar conductivity?
(A) Diaminedichloroplatinum(I)
(B) Tetraamminedichlorocobalt(III) chloride
(C) Potassium hexacyanoferrate(II)
(D) Hexaaquochromium(II) ...
2
votes
1
answer
3k
views
Does electrolysis of aqueous tin(II) chloride produce Cl₂, SnCl₄ or both?
When applying a current to an aqueous solution of tin(II) chloride, tin crystals grow from the cathode. However, I'm not sure about the anode. It seems like there are two possible reactions:
$$\ce{2 ...
3
votes
0
answers
157
views
Removing Tungsten Trioxide from Tungsten Electrode
I need a very sharp tungsten electrode, and I think radial electrochemical etching with sodium hydroxide is the way to go. The problem therein (I think) is that the etching will cause an oxide layer ...
8
votes
1
answer
20k
views
What visual observations can confirm that a reactant is the limiting reagent?
I have this lab question for the lab called Copper Collection Stoichiometry, where we choose an amount of the limiting reagent (iron) for a reaction between copper (II) sulfate and iron. We are to ...
2
votes
3
answers
7k
views
How to convert sodium aluminate back to sodium hydroxide?
I had dissolved a bunch of aluminium foil in an aqeous solution of sodium hydroxide. The resulting solution consists mainly of sodium aluminate with very little excess sodium hydroxide.
What I want to ...
4
votes
4
answers
7k
views
Why is zinc deposited on copper when boiling an aqueous zinc sulfate solution?
I did an experiment where I dissolved 30 grams of zinc sulfate in water and boiled it with strips of solid zinc metal and strips of copper metal and a layer of zinc was deposited on the copper.
I ...