Questions tagged [electrochemistry]
The branch of chemistry that deals with the study of redox reactions and how they can be applied to generate electricity (in electrochemical cells) and to carry out non-spontaneous reactions using electricity (electrolysis).
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Why the electrons in the electrolytic cell don't flow from cathode to anode?
In electrolytic cell electrons are transferred from anode to cathode via wire. These electrons are those which are given by anion to the anode. But if anode is connected to the positive terminal of ...
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Electrolysing two salts with the same anion
Assume that I prepare solutions of sodium chloride (NaCl) and potassium chloride (KCl) in equal molarity, then combine them together to form a single homogeneous mixture. Then I electrolyse this ...
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What is brown/red precipitate in battery acid
I am working on recovering some lead acid batteries that have lost some of their capacity. I drained all of the sulfuric acid out and there was an awful lot of brownish red precipitate in it. My ...
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Finding Ksp from electrochemical data? [closed]
I've been stuck on this question for a week now and can't find a similar problem anywhere. Can someone explain how to solve this?
An electrochemical cell is created based on the Zn(NO3)2 (aq) | Zn (s) ...
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Over-potential of oxygen in electrolysis of NaCl solution [closed]
Being told that over-potential causes the evolution of chlorine gases in the electrolysis of dilute sodium chloride solution, I feel very confused.
I have conducted an experiment on the electrolysis ...
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How do I explain that voltage decreases when increasing the concentration of the cathode in a voltaic cell?
I just finished a lab experiment in which I built a voltaic cell with copper (II) sulphate and zinc sulphate. My experiment was to identify the correlation between the concentration of copper (II) ...
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What is the ionic conductivity of the hydroperoxide ion?
Hydrogen peroxide is supposed to dissociate as
$$\ce{H2O2 <=> H+ + HO2-}$$
But I can't find a source for the conductivity, $\lambda$, of the hydroperoxide anion $(\ce{OOH-}$ or $\ce{HO2-})$ on ...
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Electrochemical double layer formation
I was revisiting some of my notes about the electrochemical double layer but I have some doubts, and even the textbook of Bard and Faulkner could not really help.
In electrochemical systems, at the ...
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Carrying out electrolysis of very dilute NaCl for a long time
I find a similar question in stack exchange (What will happen if the electrolysis of Brine takes place for a long time?), yet it does NOT seem to respond to my question.
Suppose I am electrolysing a ...
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What is the difference between standard Gibbs energy and Gibbs energy of formation?
Good day guys,
I am reading a book on electrochemical engineering, I came across some definitions of Gibbs energy and I am a bit confused as the book does not go into a lot of detail.
The book first ...
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Comparison of the electronegativity of halogens and the reduction potential of halide ions
While studying the electrolysis of aqueous solutions, we often have to deal with more than one ion at the anode and cathode, and we have to determine which one will discharge. For example, if we have ...
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Can a multimeter be used to measure PH?
I would like to feed my garden a solution of water and Trisodium Phosphate (TSP), but I am uncertain of the correct amount of TSP to water ratio. Too acidic or too basic of a solution can harm my ...
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Universal indicator solution in electrolysis
Sometimes universal indicator solution, or whatever acid-base indicators, is added into an electrolytic cell to indicate the change in pH at electrodes over time.
I wonder, if universal indicator ...
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Acid dissociation constant from conductometric data
$\ce{0.007 M}$ aq. solution of anilinium hydrochloride had molar conductivity equal to $\pu{119.4 S cm2 mol-1}$, which became $\pu{103 S cm2 mol-1}$ when a few drops of aniline were added to the ...
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What is the **minimum** externally applied voltage for an electroplating setup?
I am trying to plate a piece of iron jewelry by using a silver anode and a silver nitrate solution. I am confused on how to calculate the voltage needed. Since silver is oxidized at the anode and then ...
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Advise on performance vs cost of the Berkland-Eyde Process for direct synthesis of Nitric Acid from atrmospheric air
I am new to chemistry, having gone down an electronics route in my career, so I decided to pick up where my 'O' levels ended (many years ago) and make a better understanding of the topic a sort of ...
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Find cell configuration notation for permanganate in acidic medium
They gave us an unbalanced reaction of permanganate and iodide in acidic medium, and ask to balance the reaction using redox methods and the write the cell configuration notation for the resultant ...
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Collapse of Butler-Volmer equation into the Nernst equation at equilibrium potential
How does the Butler-Volmer equation collapse into the Nernst equation when applying the equilibrium potential current? I don't know where to start, and this source I used (https://www.sciencedirect....
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Where does the relation Λm=κV come from? is it experimental?
I was learning about molar conductivity in electrochemistry and this relation
Λm=κV
came up in my textbook. it somehow '...
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Is the half-wave potential concentration dependent?
As I was refreshing my knowledge on cyclic voltammetry, I came across the following doubt.
Is the half-wave potential concentration dependent or is it not?
If we look at this graph, let's assume we ...
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Why does the Nernstian cell potential remain ideally constant during charge or discharge of an electrochemical cell?
I was reading a couple of papers by Prof. B E Conway, including his book "Electrochemical Supercapacitors", where he came across this statement that the Nernstian potential of an ...
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Determine potential and electric field distribution between electrodes
I want to analytically determine a simplified potential and electric field distribution around planar electrodes, and an 40nm square electrode in an 50nm insulating well.
I think that the Poisson-...
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Why is concentration never zero for zero order reactions? [closed]
By formula of zero order reaction:-
$$C_t=C_o-kt$$
The concentration should be zero at $t=C_0/k$. But in some books and websites I saw that graph between concentration and time don't touch the X-axis. ...
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Cyclovoltamogram of silver in solutions of its insoluble salts
Hello I was dealing with the following question in my electrochemistry course:
Sketch cyclic voltammograms for the silver oxidation and reduction in different
electrolytes. Assume electrochemical ...
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Does electroplating with copper takes less time than electroplating with zinc?
is electroplating with copper quicker than electroplating with zinc -- assuming that in both scenerios the cathode is steel, the surface area, the current, the thickness are the same, and the ...
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Electrodeposition using Ionic liquids
I haven't found to many research papers yet, but would it be possible to electroplate nickle-aluminide onto a niobium alloy using an ionic liquid? I know certain industries are already using this ...
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Can you give an example of an electrolytic process that has high Faraday efficiency but low energy effiency
I want a nice example to help illustrate the conceptual difference between these terms to a biologist.
I found this figure which might be helpful.https://www.researchgate.net/publication/...
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Addition of NaCl to the Anode Side of a Zinc-Copper Votaic Cell
I used a NaCl solution with a Zinc electrode in an otherwise standard voltaic cell with a Potassium Nitrate Salt Bridge and Copper Sulfate solution in the Cathode side. All the solutions were 1M.
I ...
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Why does metal atom get an effective potential difference in voltaic cells [closed]
Why is it that metal atoms , experience this potential difference when immersed only in their salt solutions. When they are in contact in real life we cannot see current conducting through it.
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If E° of a Half Cell is based on the chosen reference Electrode (Generally SHE) then how is the equation ΔG°= -nFE° be valid for a Half Cell
For example let us take the reaction:
Zn(s) ---> Zn^2+(aq) + 2e^-(aq) ;ΔG°, which we are considering as our half cell
And now suppose, by taking the value of E° of SHE(Standard Hydrogen Electrode) ...
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Positive and negative terminal in an electrolytic cell
In the figure below, which electrodes are negative terminals? I have worked out that E: Cu2+ -> Cu, F: OH- -> O2, G: H+ -> H2, H: OH- -> O2. However, I am still confused about the polarity ...
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In which medium is Potassium Permanganate a better oxidising agent?
I was in chemistry class just now, and my chemistry teacher gave us three reactions:
Reaction 1: $\ce{MnO4^- + e- -> + MnO4^2- (basic medium)}$
Reaction 2: $\ce{MnO4^- + 4H+ + 3e- -> + MnO2 + ...
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Ablation of pyrolitic graphite utilizing electrochemical means
I am looking for a process to ablate the surface of a pyrolytic graphite (PG) sample.
I am thinking that an electrochemical process might be the answer; however, since this is not my field, I am ...
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Calculating the solubility product for a salt in a metal-metal insoluble salt electrode
When trying to find the solubility product of a salt in a metal - metal insoluble salt electrode, I find that I am getting a different answer if I consider the cell to be a concentration cell and if I ...
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Can zinc carbon batteries be made in the way gen did in dr. Stone? [closed]
So in episode 23 of the anime dr. Stone https://www.youtube.com/watch?v=faQ2EVj7SrQ a character named gen was making zinc carbon batteries by using manganese and I’m pretty sure it wasn’t manganese ...
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Where can I find large glass covered stir bars?
I am looking to use a large stir bar, on the order of 100mm, that is not coated with any Teflon or PTFE. This is because my application is measuring PTFE in water and a stir bar can effect the results....
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Standard electrode potentials
I know that many substances have their own standard electrode potential and they can be arranged in he electrochemical series. For example, the standard electrode potential of iron is -0.440V.
Since ...
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What is the reason why galvanic series is in it's specific order?
I'm trying to understand why galvanic series molecular entities are in the order they are in.
Why does $\ce{Cu(s)}$ reduce $\ce{Ag^{2+}}$ ions but not $\ce{Pb^{2+}}$ ions?
there seems to be some kind ...
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Possible technique for measuring pH in solutions
I would like to develop a device that measures pH in aqueous solutions. I'm not a chemist, but I have some basic knowledge about electrochemistry. So, I thought I could use two electrodes quite close ...
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Voltammogram during calibration is not smooth
During calibration for differential pulse voltammetry, the voltammogram obtained has two distinct peaks. I am not sure why I am getting two peaks in the range from $\pu{-0.6 V}$ to $\pu{-0.9 V}.$ I ...
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Can we add specific conductivities at any concentration?
Suppose we have specific conductivities of $\pu{0.1 M}$ $\ce{K+}$ and $\pu{0.1 M}$ $\ce{Cl-}$. Can we add their specific conductivities to get specific conductivity of $\pu{0.1 M}$ $\ce{KCl}$?
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What is the difference between using an oven or an IR lamp to dry the coatings of fuel cells?
I wondered how the morphology of the catalyst coating for fuel cells changes if it is dried either in a conventional oven (40 °C, 60°C, 80°C) or under an IR lamp.
I am pretty certain that it changes, ...
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How exactly does the Nernst equation account for temperature? [duplicate]
I am doing an experiment that involves changing the temperature of the electrolytes in a voltaic cell and seeing the effect on the initial voltage produced. I'm a bit confused because if I use the ...
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Is it possible to make a reversible "Solid State" Hydrogen fuel cell using Ammonia Borane and Iron Oxide? [closed]
Well, I saw this video about hydrogen reduction, in which pure hydrogen gas is exposed to iron oxide at high temperatures, producing water vapor and leaving pure iron behind.
And as such, I wondered ...
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Can an electrode run out of the active species?
I have a background in solid state physics but am new to electrochemistry. I have been following the example of a physical chemistry (Mortimer) book that looks an electrochemical cell with a hydrogen ...
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Is preferential oxidation/reduction at electrodes only dependent on the reduction potential or is it also dependent on kinetics?
It is commonly taught that in electrochemical cells where there are 2 different chemical species that can be oxidised/reduced, species with more positive actual reduction potentials (concentration ...
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How does a silver chloride electrode (Ag/AgCl) convert the potential in aqueous solution to the wire?
I am aware of the redox chemistry that happens at the electrode surface, but I'm not sure how exactly a change in electrical potential in the solution would change the potential in the electrode?
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Why is sodium p-toluenesulfonate used as a supporting electrolyte in polypyrrole synthesis?
First, some preamble: I'm currently working on my thesis, which is about the electropolymerization of polypyrrole onto carbon fiber felt. My methodology, for the most part, follows a paper by one of ...
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Why the water in an lead-acid battery isn't self-electrolysed (at any significant rate)?
I'm reading Detchko Pavlov's Lead-Acid Batteries: Science and Technology (maybe an old version than the link) and in the first chapter the book mentioned "it is currently unknown why electrolysis ...
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Why would my pH meter have changed its voltage setpoints?
I'm using a Thermo Scientific Orion Dual Star pH/ISE Dual Channel Benchtop Meter.
The manual says that a $\mathrm{pH}~7$ buffer should read about $\pu{0 mV},$ and a $\mathrm{pH}~4$ buffer should read ...
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