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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1answer
437 views

What does the osmotic pressure do in an electrolytic solution?

I have learnt that in an electrochemical cell, the osmotic pressure in the solution hinders the flow of ions from the electrode to the solution, rather some ions may accumulate on the electrode ...
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0answers
47 views

Why is $E°_{cell}$ not $\Delta E°_{cell}$?

$E°_{cell}$ is the EMF of the cell for a reaction with respect to standard hydrogen electrode(SHE). So why don't we represent $E°_{cell}$ or $E_{cell}$ by $\Delta$ symbol, in the same manner in which ...
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0answers
40 views

Electric fields in a galvanic cell

I have read hat there is two types of electric fields exist in galvanic cell.I understand E because of charges accumulated on electrodes but what about other E -field? What does cause this field and ...
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1answer
619 views

Electrochemical Cell

Now in an electrochemical cell , we make use of the fact that whenever there is a potential drop , electrons will flow from lower to higher potential as for a potential drop , there must be an ...
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2answers
401 views

What dictates cathode vs anode nomenclature use?

what was the justification for the use the cathode and anode terminology in IEF? There is no redox taking place in IEF, just proteins interacting with an electric field
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6answers
477k views

Positive or Negative Anode/Cathode in Electrolytic/Galvanic Cell

In a galvanic (voltaic) cell, the anode is considered negative and the cathode is considered positive. This seems reasonable as the anode is the source of electrons and cathode is where the electrons ...
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1answer
154 views

Is a discharged battery in a state of chemical equilibrium?

A reaction that has reached chemical equilibrium no longer shows changes in reactant and product concentrations, but forward and reverse reactions are still going on. I'm confused whether a completely ...
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0answers
54 views

Is pH in a charged hydrogel and its supernatant solution constant?

Let us assume we deal with ideal systems without interactions. The gel phase and the supernatant solution phase are in thermodynamic equilibrium. The supernatant solution shall consist of different ...
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1answer
28 views

In a galvanic cell,do charges accumulate on electrodes 1st (then redox occur) which produce E in the wire when we connect between electrodes? [closed]

We study that when we connect a wire between the terminals of a battery ,an electric field in established between terminals due to potential difference .Is the potential difference result of ...
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0answers
24 views

How does different pH affect copper electroplating [closed]

I'm currently investigating the effect on the concentration of hydrogen ions in the copper sulfate solution on the amount of copper deposited on the cathode within a certain amount of time. I've ...
4
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3answers
16k views

Calculate the standard oxidation potential from given potentials

The standard electrode potentials for the following redox couples are given as: >$E_0(\ce{Fe^{2+}/Fe}) = x~\mathrm{V}$ and $ E_0(\ce{Fe^{3+}/Fe^{2+}}) = y~\mathrm{V}$ What will be potential $E_0(\ce{...
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1answer
128 views

Is it true that “Voigt Circuit” would be able to be fitted to various electrochemical impedance spectra?

"Voigt Circuit" which is a series combination of Voigt elements (i.e. parallel RC's), is commonly used for Kramers-Kronig relations checking; and as I imagine it is generally believed to be able to be ...
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1answer
41 views

General Oxidant - Reductant Battery

In general, is it true that if I connect an aqueous oxidant to an aqueous reductant via a wire then a current flows along the wire? In particular, does current flow in the following scenario? Imagine ...
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2answers
268 views

Can I use a digital multimeter as substitute for a zero resistance ammeter?

I am testing the galvanic corrosion between two metals, following ASTM G71. In this method, a zero resistance ammeter was the material presented to determine the galvanic current measurements. ...
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2answers
188 views

Amperage for the electrolysis of water?

I am electrolysing water using several different potential catalysts for my eight grade science fair project. The electrolysis will be running at 2 to 2.5 volts over nickel electrodes, as I do not ...
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0answers
26 views

How does one electroplate Lithium onto a conductive metal? [closed]

In this case the anode for electroplating would be the Lithium and the cathode would be any conductive metal. Unfortunately Lithium reacts violently with water, which is the basis of most electrolyte ...
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2answers
1k views

Nernst equation for a fuel cell when gases are stored separately

I have run some tests with a PEM fuel cell and the voltage we have found was $1.44\ \mathrm{V}$. Given that the standard potential for a fuel cell is $1.229\ \mathrm{V}$ what is causing the difference ...
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1answer
41 views

Electrolytic refining of precious metals — why the anode rather than the cathode? [closed]

In electrolytic refining, metals like platinum and gold are deposited as anode mud. Why aren't they deposited on the cathode since they have higher reduction potential?
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2answers
575 views

What is entropy change in electrochemistry?

I keep seeing entropy change (or reversible effects) and irreversible effects (Joule heating) when reading about charging and discharging of Li-ion batteries. I understand the Joule heating part (the ...
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3answers
5k views

Hydrogen fuel cell - why do the H+ ions move through the electrolyte

Consider the following hydrogen fuel cell http://butane.chem.uiuc.edu/pshapley/Enlist/Labs/FuelCellLab/FuelCell.html At the anode, hydrogen is oxidised (losing electrons). My first question is this: ...
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1answer
111 views

Why does magnesium deposit during electrolysis of a molten mixture of MgI2 and AlBr3?

During the electrolysis of mixed salts, I read, and was taught, that the cation with a higher ionization energy would deposit at the cathode. I was also told that you cannot use the standard electrode ...
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0answers
34 views

Why not create a latent heat battery?

Since latent heat is not sensible, it seems like it would be useful in creating an efficient battery. Sensible heat interferes with electron flow in standard lead-acid and other batteries. The latent ...
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1answer
161 views

Application of Nernst Equation in Potentiometric titration of Fe2+ with Ce4+

It is well Known that to find $E_{cell}$ during titration of $Fe^{2+}$ with $Ce^{4+}$ we consider 3 domains: Before Equivalance point , $E_+ = E_{Fe^{3+}/Fe^{2+}}^o+\frac{RT}{nF}log\frac{[Fe^{3+}]}{...
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28 views

why is there a net current at halfwave potential?

Im wondering why there is a current measured at a halfwave potential? According to my understanding at the halfwave potential of a diffusion controlled reduction or oxiation at an electrode, there is ...
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0answers
71 views

Can I reverse an iron redox reaction with potassium hydroxide and electricity?

For a school project, about clean energy, me and my team are trying to build an iron battery. We are using a piece of iron (anode), potassium hydroxide (electrolyte), carbon electrode (cathode) ...
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2answers
3k views

Will magnesium undergo a redox reaction with zinc(II) or copper(II)?

Magnesium can do a redox reaction with $\ce{Cu^2+}$ as well as with $\ce{Zn^2+}$, since Mg has the lowest reduction potential $E_0$. (I am aware that a reaction may or may not be feasible as redox, ...
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1answer
514 views

Do We change sign of electrode potential when reversing an equation?

I have a cell equation as: $$\ce{2Cr^0 + 3Cd^2+ -> 2Cr^3+ + 3Cd^0}$$ I am provided the standard reduction potentials as: $$\begin{align}\ce{Cd^2+ + 2e- &-> Cd} && E= \pu{-0.4V}\...
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0answers
36 views

Surface modelization of an electrode

I am trying to model the interaction between an electrode and a saline solution through an RC circuit. A reference electrode is placed in the saline solution to measure the voltage between the ...
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1answer
8k views

Calculate how much hydrogen or oxygen will be produced in the electrolysis of water

Is there a way to exactly calculate the quantity of hydrogen or oxygen in a water electrolysis? I am thinking of a plain and simple electrolysis like an anode and kathode in salted water separating ...
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3answers
154 views

Is it possible to generate electricity by using two inert electrodes in a galvanic cell?

The Daniell cell has two active electrodes, meaning that both the copper and the zink electrodes participate in the redox reaction. However, in a lemon battery for example, the copper electrode is ...
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0answers
24 views

Nickel electroplating diamond grinding wheels

We can electroplate nickel on steel base with any density as we wish. For small diamond grits by pumping the solution we can electroplate the diamonds on the tool. But after some testings we find ...
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0answers
25 views

What is the cause of yellow discharge in beaker during the electrolysis of copper electrodes using copper sulfate electrolyte?

I have conducted an electrolysis experiment using a copper anode and cathode, and copper sulfate solution in a beaker connected to a power source using alligator clips. I varied the voltage and ...
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0answers
27 views

Electrolytes for Anodization at Home

I'm looking into anodization, and all the people doing it seem to have sulfuric acid as their first choice electrolyte, while others use sodium metabisulfate. Having simple access to exactly neither ...
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2answers
145 views

What is the safest way to hook up car battery jump cables and why? [closed]

I know that when both connecting and disconnecting battery jumper cables between two car batteries there is a prescribed safe way to do it. I can never remember the correct way because I can’t ...
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3answers
2k views

Could I settile for galvanized steel over stainless for salt corrosion resistance?

Bear with me, I'll get to the chemistry soon. I have a float tank that I want to attach a skimmer to. Unfortunately, the enclosure is weakened by cutting a hole out of the ABS plastic. The weight ...
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2answers
3k views

Why does NaCl act as a catalyst for the reaction of CuSO4 + H2O + Al?

I am analyzing a reaction between water sulfate copper and aluminum. A chunk of $\ce{Al}$, e.g., aluminum foil. I realize that a layer of $\ce{Al2O3}$ forms on the surface of the $\ce{Al}$, ...
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2answers
13k 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
100 views

Electrolysis of molten sodium chloride [closed]

Can somebody explain me the electrolysis of molten $\ce{NaCl}$ via electrode potential? Reduction potential of $\ce{Cl-}$ is -1.36 V, while sodium metal is -2.76 V, but still sodium is reduced and ...
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1answer
74 views

Would a salt bridge work through which the ions could not diffuse into the half cells?

Instead of covering the ends of the salt bridge in an electrochemical cell with a membrane, one could also plug them on both sides with a conductive non-porous material, for example gold, which doesn'...
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4answers
327 views

How can a neutral atom attract electrons when it's supposed to have zero charge?

A neutral atom is an atom with an equal number of protons and electrons We know the force of attraction between the proton and electron is equal and assuming that: one proton's positive charge ...
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2answers
184 views

Is there a potentiometric method for monitoring salt formation in organic solvent?

I work in a pharmaceutical R+D lab, and currently aim to develop a validatable potentiometric method for determining the optimal amount of acid to add to a basified small organic molecule for ...
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1answer
38 views

Confusion about the electrolyte in an electrochemical cell

So the cathode is magnesium and the anode copper. The question asks why silver nitrate would not be a good electrolyte. I am confused. Also is the anode always inert in these cells?
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2answers
80 views

In a half cell reaction, Is the potential halfed?

If you have an electrolyte of $\ce{Zn^2+}$ and $\ce{SO4^2-}$ (Neutral) Then you dip in it a Zinc electrode. Zinc potential is $\pu{-0.74 V}$ (relative to SHE). So that means there is a $\pu{-0.74V}$ ...
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3answers
249 views

Why isn't my galvanic cell making enough voltage?

I'm in kind of a pickle here. I made a galvanic cell of Lead and aluminium for a chemistry internal assessment but unfortunately, it didn't turn out so well and neither me nor my teacher has any clue ...
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2answers
8k views

Effect of pH on electrolysis

I understand (more or less) that acidification of water helps in the dissociation of water into ions. Acids easily dissociate into ions in aqueous solution. So, accordingly, the hydrogen from the acid ...
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1answer
126 views

Why is the peak-to-peak separation of cyclic voltammetry is 57 mV?

I'm studying CV, and I wonder if I can calculate the peak-to-peak separation of CV for a reversible redox system. I found that the separation is 57 mV on my textbook, and my teacher taught me that is ...
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2answers
7k views

Purpose of electrolyte in a galvanic cell

I am confused as to why galvanic cells have electrolytes. For example, a zinc-hydrogen galvanic cell has a zinc sulfate anode electrolyte and hydrochloric acid cathode electrolyte. The overall ...
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1answer
835 views

How exactly does a battery work (specifically Pb/H2SO4/H2SO4/PbO2 lead acid battery)?

Specifically talking about the lead-acid battery, I understand (or think I understand) this much: The anode, in the presence of the electrolyte, $\ce{H2SO4}$ will be oxidised: $$\ce{Pb (s) + SO4^2- (...
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1answer
80 views

Why doesn't anyone manufacture 4.5 V cells?

Every 4.5 V lantern batteries are a series of three 1.5 V cells. It would have more capacity if it consisted of single 4.5 V cell. But I don't see any 4.5 V cell. According to Wikipedia's Standard ...
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0answers
67 views

Electrolytic cell - Potentials

I'm an electronic engineer student and I'm trying to understand the basics of electrolytic cells and practical values' meaning. Based on my figure and electrode potencial values (Vce, Vre and Vwe), ...