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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37 views

is electrolysis of water less efficient with warm water? E.g 40, 50, 60... °C

I see there is High-temperature electrolysis which is a whole different animal than room temp electrolysis. I want to know if electrolysis of lukewarm water will behave much differently. My guess is ...
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26 views

Why a Li-ion battery, when in storage, is better kept around 85% instead of 100%?

I discovered that in my laptop settings, I can select an option that is best chosen when the laptop is mainly connected to AC power, and apparently keeps the battery at a lower SOC. I found this ...
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45 views

About the acidity of phenytoin

Can you explain why phenitoin is weak acid even though nitrogen is base? Does carbonyl group always make structure acid? If this structure doesn't have carbonyl group, would it be base not acid?
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28 views

Electrolysis in Electrophoresis of proteins and DNA

Can electrolysis happen in an electrophoresis assay (such as SDS-PAGE)? To perform electrophoresis, the substances must be dissolved in an aquatic buffer with a previously determined ionic strength. ...
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29 views

Is it possible to make a concentration cell without ion-permeable membrane?

I struggle to understand the use of ion-permeable membrane (or salt bridge). https://en.wikipedia.org/wiki/Concentration_cell If i pour two solutions with different concentration, why do you need the ...
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25 views

Effect of concentration on voltage from the perspective of energy

As I understand it, the voltage in an electrochemical cell is due to the electrons transferred having a decrease in electrical energy as they go from one species to another. I assume that this change ...
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46 views

What is the difference between these notations and terms?

I can't tell if they're being used interchangeably or if there's some nuanced difference betweem them. Here they are: $E^∘$ $E_0$ $E_h$ $E^⦵$ If I understand correctly, electrode potential is the same ...
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17 views

How to use anodic and cathodic overpotentials to calculate electrolytic energy efficiency?

I am trying to calculate the energy efficiency for $\ce{CO2}$ reduction to formate, coupled to water oxidation based on literature data. $$\ce{CO2 + 2e- + 2H+ -> HCOOH}$$ $$\ce{H2O -> 2H+ + 1/...
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33 views

What Determines the Value of Symmetry Factor (Charge Transfer Coefficient) and What is its Connection With Transition State Structure/Configuration?

I know that symmetry factor determines symmetry of energy barrier for reduction and oxidation. It is an fraction of electric potential energy difference of electron in electrochemical double layer ...
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23 views

Electorchemical Systems (Newman 3rd edition) problem solving

I am trying to solve the very first problem (Problem 1.1) of Newman 3rd edition book. The book problem goes as follows: 'Starting with the following equation for the concentration overpotential: $\...
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35 views

Why is zinc electrode at a higher potential than copper electrode in a galvanic cell?

I read somewhere that this happens because of better shielding of outer s electrons due to completely filled d orbitals of zinc, but I didn't understand it. Since Zn has an electronic configuration of ...
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26 views

Variation of battery potential with current density

It is found experimentally that the potential of an electrochemical cell with applied current density varies as follows: To produce the passage of current through a cell it is necessary to apply a ...
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79 views

What happens when solution containing two or more cations are electrolysed at an excess potential?

$\pu{250 mL}$ of a waste solution obtained from the workshop of a goldsmith contains $\pu{0.1 M}$ $\ce{AgNO3}$ and $\pu{0.1 M}$ $\ce{AuCl}$. The solution was electrolyzed at $\pu{2 V}$ by passing a ...
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How to estimate gas yield from polarization curve of the electrolyser

A good characterization of electrical properties of the alkaline water electrolysis of the water is its polarization curve. Is there a reasonable way to estimate gas yield for each point of the ...
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52 views

Weight Percent Standard State

I am having one doubt in weight percent standard state...Please see the quote(Taken from the legendary thermodynamics book by David Gaskell): If deviations from Henry's law occur below 1 wt %,then ...
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39 views

Surfactant micelles from glassware

FYI to start- I'm not a chemist by training, so assume I'm missing some basic knowledge of the field. I've been trying to do some electrodeposition with an iridium tetrachloride-based solution, and my ...
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36 views

Question about reversible chemistries in anode and cathodes

I've been reading a lot about cathode and anode chemistries recently involving Li-ion cells and solid state chemistries. What makes a decent anode seems to make sense as it is a lower potential area ...
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25 views

Do the ions of the two electrolytes mix in the salt bridge of a galvanic cell? [duplicate]

I read several times in books and on the internet that they do not, but this illustration on the Wikipedia confused me because of the zink and the sulfate ions are written above the arrow (image ...
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61 views

How does the cation radius affect the rate of increase of the electrical conductivity of a salt in aqueous solution?

Potassium chloride has a greater ionic radius than sodium chloride. How does this affect the fall in rate of increase in conductivity as concentration concentrations? I know the following factors ...
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24 views

Can I mix pressures and concentrations when finding equilibrium constant? [duplicate]

In order to find the equilibrium constant (or reaction quotient) I know I can find the value as the products over reactants raised to coefficient exponents. But, in all of the problems I have had to ...
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15 views

What does a sigmoidal and non-sigmoidal shape of a oxygen reduction reaction (ORR) voltammogram mean?

While testing materials for their ORR performance, one can encounter linear sweep voltammograms that have a well defined diffusion plateau and a good sigmoidal shape. On the other hand, the opposite ...
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34 views

Methane Sensor electrochemical reaction

When using a methane sensor a voltage is applied and much like electrolysis if the voltage is above the decomposition potential a reaction happens. Flammable gasses like methane are easily oxidized ...
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213 views

How to find number of moles of HNO3 behaving like acid in a redox reaction?

In the reaction $(1)$, how to find the number of moles of $\ce{HNO3}$, which is behaving like acid? The reaction is given as follows: $$\ce{Sn + HNO3 -> Sn(NO3)2 + NH4NO3 + H2O} \tag1$$ To find ...
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138 views

How do you purify gases formed in electrolysis with a potassium hydroxide electrolyte?

I am interested in the $\ce{KOH}$ vapor that is released with my gasses during electrolysis. I have two questions. What would be the best place to start research on the $\ce{KOH}$ vapor produced in ...
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35 views

Reason for no change in electrode potential in reference electrodes

Reference electrodes such as the saturated calomel electrode and silver chloride electrode have a constant potential because the $\ce{Cl-}$ concentration (or, to be more precise, the activity) is ...
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85 views

Reduction potential for reduction of O2 to H2O2 in alkaline medium

I've read that $\ce{H2O2}$ is a good reducing agent in alkaline medium and can reduce $\ce{Fe^3+}$ ions to $\ce{Fe^2+}$ in alkaline conditions. But I need to verify this using the standard reduction ...
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178 views

Aluminum Hydroxide electrolysis

Does molten Aluminum Hydroxide break up to aluminum, water, and oxygen by electrolysis? It's easy to write the equation $$\ce{4Al(OH)3 -> 4Al + 6H2O + O2}$$ but is this actually possible?
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32 views

Mass Transport and Ion Transport - Li-ion Batteries

I am new to the field and trying to grasp the theories/ physical phenomena behind the Li-ion batteries. I came across two phenomenons 'Mass transport' and 'Ion transport'. As I understood Mass ...
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114 views

Did both temperature of nernst equation same

I saw the nernst equation I have a doubt.Did the temparature at which Standard potential is measured is also the temparature at which electrode potential is measured. I mean Did the temperature (T) in ...
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237 views

Conductometric titration curve when KCl is gradually added to AgCl solution [closed]

The situation given is that we are performing conductometric titration where KCl is gradually added to AgCl solution and we have to plot the variation of conductivity with the volume of aq. KCl added. ...
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29 views

A question about potential difference across a membrane

Membrane potential of living cells arising from the difference of concentration of ions on both sides of the membrane, but why didn't someone use selective polymers as AEM (Anion Exchange Membrane) ...
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67 views

Log(Q) is zero, therefore the effect of temperature change is unaccounted for by Nernst Equation?

I have an internal assessment on Nernst Equation. The experiment is seeing how changing temperature effects cell potential. The solution are zinc and copper sulfate with each having concentration of ...
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1k views

Do ions in a salt bridge come from the half cells in electrochemistry?

I understand the basics of electrochemsitry and galvanic cell, where there are half cells where either an oxidation or reduction reaction occur, and electrons moving between the wires provide the ...
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33 views

Is the thermodynamic stability against reduction/oxidation of an electrolyte dependent on the electrode material?

Consider an electrochemical cell with an inert Pt working electrode (WE) and some electrolyte that irreversibly decomposes upon oxidation. A minimum potential $E_{min}$ (vs. some reference) needs to ...
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181 views

What happens when you run house electricity through salt water?

What happens when you run house electricity (120VAC) through salt water? (with standard copper wires!) Well, in https://youtu.be/dcrY59nGxBg , an interesting experiment was conducted to find out! At ...
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326 views

Calculate voltage, cost and time of nickel coating

To nickel with a bath of $\ce{NiSO4}$ a cathodic current of $\pu{0.3 A/cm2}$ is applied with a square plate of side $\pu{5 cm}$ is used to nickel a certain substrate. Due to the formation of $\ce{H2}$ ...
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45 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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31 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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157 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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42 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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71 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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35 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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97 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), ...
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32 views

How to find out the value of 'n' in the equation (ΔG = −nFE)? [duplicate]

I can figure out the value of 'n' in simple equations like Fe³⁺ + e⁻ → Fe²⁺ (which would be n=1 here.) But in equations like 2Cu⁺→ Cu²⁺ + Cu, I can't figure it out. I assumed the value of n would be ...
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42 views

Electroplating boat hulls with ceramic like material containing copper oxide to prevent barnacles from sticking?

Calcium bentonite can be electroplated onto steel. After it is electroplated on to steel it has a rough and porous like surface that is very hard and tough. If you were to electroplate a thin layer ...
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76 views

Is it possible to synthesize permanganate electrochemically?

I have been researching the production of peroxy acids and other strong oxidizers. I was wondering if it's possible to produce permanganic acid if I were to cast an anode containing Manganese Dioxide ...
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54 views

Electrolysis of a calcium salt in polar aprotic solvent

If i found a calcium salt that is soluble in acetone or ethyl acetate, which are polar aprotic solvents, and attempted electrolysis, what would happen? Since polar aprotic solvents are used in metal-...
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58 views

questions about half cell of Daniell cell

My questions are as follows: For the Daniell cell, we assume that ZnSO4 and CuSO4 are 1M aqueous solutions. What if we use pure molten ZnSO4 and CuSO4 instead? Assume that we prepare an isolated half-...
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35 views

Reaction between copper and silver(I) nitrate in aqueous medium

What is the reaction between $\ce{Cu}$ and $\ce{AgNO3}$ taking place in aqueous medium? The answer given was: "Only" oxidation of $\ce{Cu}.$ My concern is: how is only oxidation of $\ce{Cu}$ ...
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28 views

What Ion gets reduced in this aqueous electrolysis?

In an electrolysis of tin(II) iodide ($\ce{SnI2}$) with led cathode and nickel anode, why is it that the tin ion gets reduced and not the nickel ion?

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