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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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918 views

Changing Temperature of a Galvanic/Voltaic Cell: Should I wait for the electrodes to also change in temperature?

I'm conducting an experiment where I change the temperature of the sulfuric acid in a lead acid storage cell. My one question in controlling the variables is that should I let the electrodes also ...
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1answer
203 views

Galvanic/Voltaic Cell: Does Cell Voltage Change When A Resistor Is Connected?

I tried making a lead acid battery. After charging for about 10 minutes, I connect the voltmeter in parallel to the cell and see that there is around a 1.2V (which is quite lower than what I predicted)...
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2answers
139 views

Lead-Acid Battery: Standard Electrode Potential

I'm making a lead-acid battery for an investigation. Since I only had sulfuric acid and lead electrodes, I decided to firstly run 2 lead electrodes through electrolysis in a sulfuric acid electrolyte. ...
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0answers
29 views

What would affect the rate of recharge of a lead-acid battery?

I am trying to perform an investigation regarding lead-acid batteries and would like to specifically look into the recharging mechanism. However, I realised that this might be quite difficult since ...
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2answers
985 views

Redox potential of a lead–acid battery

In the German Wikipedia there are two reactions on the poles of the battery shown with the following potentials: $$ \begin{align} \ce{Pb + SO4^2- &-> PbSO4 + 2 e-} &|\pu{-0.36 V}\\ \ce{...
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1answer
42 views

Redox - concentration cell

I'm studying galvanic cells and I've found a demonstration that lead me to an impossible result, so there must be a mistake, but I can't find what it is. My problem is about concentration cells made ...
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1answer
371 views

How does PEDOT:PSS work (mechanism) in Organic Electrochemical Transistors?

I have a question about the fairly fundamental theory behind the application of PEDOT:PSS in an organic electrochemical transistor (OECT) device. As at least I understand it, the ...
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1answer
787 views

What pressure units should be used when calculating electrode potential with Nernst equation?

Example 17: Calculate the electrode potential of given electrode $$\ce{Pt,Cl2 (\pu{1.5 bar}) | 2 Cl- (\pu{0.01 M})}\,; \quad E^\circ_\ce{Cl2/2Cl-} = \pu{1.36 V}$$ Solution: The reaction of ...
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1answer
5k views

Electrolysis of diluted sulfuric acid

My teacher told me that electrolysis of dil. $\ce{H2SO4}$ (concentration below $50\%$) using inert electrodes results in gradual increase of the concentration of $\ce{H2SO4}$. I can't seem to figure ...
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1answer
343 views

Oxidation of aluminum and manufacturing of electrolytic capacitors

My background is in electrical engineering. Recently I saw instructions on how to manufacture electrolytic capacitors at home by mixing sodium bicarbonate (baking soda) to distilled water, submerging ...
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2answers
66 views

Preventing oxidation of copper(I) [closed]

By aerial oxidation $\ce{Cu+}$ can easily oxidise to $\ce{Cu^2+}$. Which of the following should be added to $\ce{Cu+}$ to prevent it from oxidation: $\ce{F-}$, $\ce{Mg^2+}$, $\ce{Mg}$ or $\ce{F2}$? $...
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184 views

In a galvanic cell, do the ions from half cell move into the salt bridge?

I know that ions from salt bridge move into the half cell in order to maintain electrical neutrality. But in my book it's also given that ions move from half cell into the salt bridge. For example, ...
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1answer
1k views

Electrolytic refining of copper

In refining copper, an aqueous solution of copper(II) sulphate is electrolyzed, using impure copper as the anode and pure copper as the cathode. At the anode, metal impurities higher than copper in ...
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1answer
171 views

Electroplating copper yields rough surface?

I am attempting to electro-plate vias in a home brew printed circuit board. The medium I am attempting to electroplate is fiberglass bound together with epoxy. This is an intentional insulator. I ...
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0answers
39 views

Mechanism of hydrogen evolution on metal-oxide electrodes

I am looking into the mechanism of different electrocatalytic reaction in acidic media on metal-oxide electrodes. Reduction of on such electrodes generally happens with the help of electrons from ...
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0answers
270 views

Oxidation of Fe to Fe3+ (corrosion)

Why does $\ce{Fe}$ get oxidized directly to $\ce{Fe^3+}$ if $\ce{O2}$ is present, but only to $\ce{Fe^2+}$ if oxygen is not present? I've tried comparing the half reactions: \begin{align} \ce{Fe &...
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65 views

Electrolysis of NaCl

Given a concentrated solution of $\ce{NaCl}$ in $\ce{H2O}$ produces $\ce{H2}$ and $\ce{Cl2}$. How many liters of $\ce{Cl2}$ does it produce after $3$ hours with a current of $\pu{4 A}$? I used the ...
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250 views

What are the factors that affect the redox reactions?

In my work, I used $\ce{Co(OH)2}$ and $\ce{Ni(OH)2}$ as an active materials to fabricate as symmetric supercapacitors in which I used 1-butyl-1-methylpyrrolidinium dicyanamide as an electrolyte. From ...
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1answer
77 views

Electrolytic silver deposition

A current is applied to two electrolytic cells in a series. In the first, silver is deposited; in the second, a zinc electrode is consumed. How much $\ce{Ag}$ is plated out if $\pu{7.5 g}$ of $\ce{Zn}$...
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0answers
59 views

Do some electrons transfer if I connect with a conductor 2 solid pieces of 2 different elements with different electronegativity? [closed]

Making some researches to answer my last post, I found this article. It explains that when a piece of zinc and a piece of copper are connected with a conductor, since copper is more elctronegative ...
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0answers
22 views

Other than fuel cells, are there processes using membranes as electrodes?

I have a presentation about membrane electrode processes. I have searched the term and I have gotten some information. There are many membrane processes such as ultrafiltration, microfiltration, ...
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0answers
87 views

Cation falling off electrode after electrolysis

I'm trying to find the electrochemical equivalent for zinc in an experiment. I am carrying out electrolysis of zinc sulfate solution. According to Faraday's law, m=zq. I made a 0.1 M solution and ...
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1answer
268 views

Will nitrate be able to oxidise mercury?

We have the following data: \begin{align} \ce{NO3- + 3 e- &-> NO} &\quad E^\circ_1 &= \pu{0.96 V}\\ \ce{Hg^2+ + 2 e- &-> Hg} &\quad E^\circ_2 &= \pu{0.86 V} \end{align} ...
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0answers
205 views

Reduction potential of a complex

I am given the reduction potential of $\ce{Fe^{3+}}$ to $\ce{Fe^{2+}}$ as well as the dissociation constants $\ce{K_D}$ for a $\ce{Fe^{3+}}$ complex and a $\ce{Fe^{2+}}$ complex (effectively, the ...
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2answers
501 views

Why does copper form bubbles in vinegar in this situation?

I watched this video in which the host tries to show the principles behind the voltaic pile. The host first immersed zinc in vinegar and bubbles are observed forming around zinc. I've learned that ...
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1answer
86 views

If two atoms “fight over” one electron, who will win? [closed]

If two atoms of different elements are both missing exactly one electron in their valence shell so that they have a charge of +1 and we place an electron between them, exactly in the middle. Which ...
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0answers
28 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 ...
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1answer
95 views

How do potentiometric cells do not proceed through a spontaneous reaction like in a galvanic cell?

It seems to me that the cell setup of a galvanic cell is pretty much the same as in a potentiometric cell. However, galvanic cells just proceed the spontaneous direction of the net redox reaction of ...
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1answer
54 views

Energy level of the product in a cell reaction

I'm very new to chemistry, so please try to be as plain as possible with your answers. I'm studying the chemistry of alkaline cells: The cell I'm interested in has the following chemical reactions ...
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4answers
1k views

Is there a way to “electroplate” wood with copper?

Maybe wood can be coated with copper (II) sulphate first, or roasted in order to form a conductive charcoal (carbon) layer.
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2answers
420 views

water in redox reactions [closed]

why water can't react as anode , with metals , in a redox reaction? while studying electrochemistry, i passed through a table with certain metals , all having voltage (potential energy) less than ...
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1answer
3k 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 ...
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1answer
83 views

Recharge battery using heat

A galvanic cell works by having two electrochemical equilibriums which have a different potential. If you (theoretically) had a galvanic cell with two electrodes which have almost identical ...
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0answers
333 views

Rationalising the trend of standard electrode potentials between the +II and +III oxidation state of first-row transition metals

Trends in standard electrode potentials of d block elements: An examination ofthe $E^0 (\ce{M^3+}/\ce{M^2+})$ values (Table 8.2) shows the varying trends. The low value for Sc reflects the ...
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0answers
80 views

Computing i0 in the Butler-Volmer equation: How to interpret Wikipedia and Wolfram Alpha

So far, when using the Butler-Volmer equation, I had j0 given and could then just use I = A * j0 * [exp(...) - exp(...)], with <...
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1answer
514 views

How can a conductivity meter be used to determine the equivalence point?

I know how a conductivity meter works. Power is supplied to electrodes and these electrodes change charge. The ions in the solution will be attracted to the oppositely charged electrode. The charge ...
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0answers
95 views

Does Reduction Potential affect rate of electrolysis

I am currently doing a project on electrolysis, and I was wondering if the reduction potential (ie. $E^0$) will affect the rate of electrolysis. In other words, across different cells with differing $...
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1answer
748 views

How to calculate Debye length of a 2-1 electrolyte

I am given the Debye length to be 10nm for 0.001M KCl at 298K. I want to know its Debye length in 0.01M CaCl2. How can this be calculated? I know that for 1-1, the Debye length is inveresely ...
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0answers
222 views

Confusing statements about galvanic cell voltage [closed]

In nearly every textbook about physical chemistry or electrochemistry, the authors mention, that the Galvani potential of a half-cell, i.e. the potential difference between an electrode and the ...
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1answer
902 views

Salt bridge in galvanic cell

When we make a galvanic cell using zinc rod (in zinc sulphate solution) and copper rod (in copper sulphate solution), there is a flow of sulphate ions from the copper compartment to the zinc ...
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1answer
89 views

Why is a comma used to separate hydrogen gas and platinum when using cell notation?

I have come across many online articles and books where I see the following: Gaseous electrode Gases such as $\ce{H2}$ and $\ce{Cl2}$ can act as anode and as cathode by loosing electrons ans ...
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1answer
91 views

Relation of conductivity with electrode distance [closed]

Conductivity is defined as the conduction of ions when the distance between the electrodes is 1 cm and length is 1 cm. Say for instance we have a solution where the distance between the electrodes is ...
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5answers
2k views

Does chemistry change under high voltage?

Do chemical reactions change when you charge the entire reaction vessel plus or minus $\pu{1 MV}$ or more? Is there a name for such chemistry? I was looking at "electrochemistry" expecting to see a ...
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2answers
159 views

How connecting galvanic batteries in series actually works. “In Series” detection experiment

How I am interested in understanding what is the actual mechanism behind increasing potential in simple galvanic cell connected in series. Almost all explanations I found on internet are more like ...
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0answers
28 views

Understanding Galvanic Cells

I am an electronics guy and not into chemistry so please forgive my ignorance. A Galvanic Cell is meant to act like a pump, separating positive and negative charges, and thereby creating an EMF. ...
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1answer
65 views

How deep does a counter electrode need to penetrate the solution in electrochemical experiments?

I ordered platinum-wire counter electrodes that are shorter than I was expecting. How much should it be submerged in my solution (right now it is only the tip that is submerged)? My experiment is ...
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1answer
33 views

How exactly lithium metal is produced? [closed]

Wikipedia and other sites say that lithium metal is produced by making the electrolysis of a mixture of half lithium chloride and half potassium chloride "at about 450°C"... What is the chemical ...
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0answers
17 views

Acidic Environment and Rust [duplicate]

I'm trying to understand why in an acidic environment, rust increases. The explanations I have seen so far basically have the following, "In acidic environments the cathode for the rusting of iron ...
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0answers
446 views

Concept of Limiting Current

I am investigating the current output from an electrochemical cell. The electrochemical cell can be broken down into several stages, for example: Diffusion of reactants across a capillary Diffusion ...
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1answer
435 views

Why is the maximum work done by a voltaic cell negative [closed]

The maximum work done by a voltaic cell is given by -nFE. Why the negative sign? From what I know, a battery does positive work on the load attached to it