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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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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53 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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144 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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296 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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544 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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44 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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177 views

Problem in anode in experiment of electrolysis of brass

I am studying the electrolytic determination of copper content in brass (~58% copper, ~40% Zn and other trace elements) by using standard method BS EN 16117-1:2011. Now the electrode used for the ...
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118 views

Why does conductivity of electrolyte solutions peak at high concentrations?

I've recently done a lab about conductivity of brine over time (high concentration salt water). I passed current through salt water and measured the current over time. The graphs I got showed that ...
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67 views

capacitive contribution voltammetry

I am working with a sheet of zinc metal where there is an oxide film on it (ZnO) in passivation conditions (pH=10). I have done voltammetry measurements for different scan rates with a 3 electrodes ...
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112 views

Can corrosion from hydrogen peroxide solution model the corrosion protection activities of Al coating?

Immersion in hydrogen peroxide can make steel corrode very fast. However, the coated steel resisted the corrosion attack for a span of time, and as time passes, the coating becomes thinner. Some got ...
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186 views

Aluminium etching

I'm trying to etch a very fine pitch ($\pu{0.5 mm}$) aluminium stencil for use with SMT printed circuit board making. I've done some reading on the topic and found that the safest way probably is to ...
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59 views

Corrosion issue at large DC current

I'm no expert in chemistry, but I know that corrosion can cause great problems in systems. I'm working on a prototype, and trying to figure out if corrosion will cause issues. The setup Imagine the ...
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87 views

Oxidation of zinc in NaCl solution

I'm working with a zinc sheet in water + Nacl solution, I have adjusted the pH to 10 to develop a ZnO layer and prevent all the faradaic reactions (passivation state). I've removed the oxygen with a ...
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57 views

How do I increase the amount of electrons transferred in a battery?

I made a simple battery with $\ce{Al}$ as anode electrode with $\pu{0.7 M}$ aluminum sulfate electrolyte. Platinum is my cathode electrode with $\pu{2 x 10^-4 M}$ $\ce{KOH}$ solution. I am generating $...
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357 views

How to determine the equivalence point of a titration of a mixture.

Today, I'm graphing the titration curve for a mixture, to be precise, this particular case: In order to get this done, i've been following wisely the mantra of "The strongest species (oxidizing and ...
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21 views

How can I relate the conductivity (uS/cm) at various temperatures of an aqueous solution of NaCl with ionic strength?

Can someone give the relationship between conductivity (uS/cm) with ionic strength please ? In some sources they that there is a linear relationship with a constant, but with no explanation to come up ...
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87 views

chemical reaction that causes electrolysis of salt water without adding electric current

I am producing hydrogen using house hold items in a capacitor like arrangement in salt water. I assume this is chemical electrolysis. The apparatus produces gas for many weeks that burns orange. Its ...
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72 views

Flame color vs electrical discharge color

I don't know the right terms to frame the question but here it goes: Neon and argon give their characteristic colors when a current is passed through them at low pressure. Balmer series etc, I ...
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820 views

Differences between galvanic cells and Li-ion?

There are clearly some differences between the classical galvanic cell and the Li-ion batteries, but if one looks at the schematics, they looks a bit similar. Please see below: a) The galvanic cell: ...
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714 views

Why does the Oxidizing agent have to be higher than Reducing agent for a redox reaction to spontaneously occur?

On the Standard Reduction Potentials of Half-Cells table, why does the Oxidizing agent have to be higher than Reducing agent for a redox reaction to spontaneously occur?
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686 views

Concentration of gas phase in Nernst equation

What if one or both electrodes are in gas phase? Use PV=nRT? Also the definition of hydrogen electrode gets a little sketchy if we use PV=nRT to write it's concentration, the electrode potential doesn'...
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88 views

Alternative to OLI simulation software

I work with modeling a number of aqueous solutions, but mostly it boils down to single-component saline solutions. The industry standard for determining various saline solution quantities such as ...
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28 views

Why do we always represent only the hydrogen evolution?

In corrosion of aluminium or magnesium for example, we have the anodic reaction which is the dissolution of the metal but for the cathodic reaction we only represent the hydrogen evolution. How about ...
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62 views

Seeking an explanation of synthetic marcasite

At least one widely available commercial product is called 'synthetic marcasite,' and perhaps two or more. The most prominent is dark gray 'synthetic marcasite' for cheap jewelry. Possibly different ...
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84 views

Why the current of double layer charging is independent of potential?

i-V curve of double layer charging has a rectangular shape. Why when increasing or decreasing the voltage, the current remains constant? Or I can ask, how the double layer structure is changing by ...
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46 views

Why are there so many reactions for the discharge of LiCoO2?

I've just managed to understand a bit the meaning of having the notation of 0.5 in a molecular formula, when I found a set of multiple notations for the same discharge process that started to confuse ...
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32 views

ZnO layer as a passivity layer

I have bought a zinc sheet and with SEM I can see a ZnO layer, which is a passivity layer. But when I connect this sheet to a conductive wire, le zn sheet is conductive too. Is that normal ? the ZnO ...
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514 views

Why does my voltaic pile produce a higher voltage then predicted?

In my chemistry class we are building our own voltaic cells and trying to produce as much current as possible with materials we are given using redox chemistry. My lab partner made a battery without ...
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4k views

Chemical Reactions at the Cathode of the Leclanche Cell

In the dry cell, the overall reactions that occur are: $$\textbf{anode:}~~~ \ce{Zn -> Zn^{2+} + 2e^-}~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~$$ $$\textbf{cathode:} ~~\ce{2NH4+ + ...
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19 views

Why do we have surface charges on a polymer sheet immerged in water ?

I am working with a conductive polymer sheet where I have dropped off a drop of water (with ions). I have plugged the polymer with a conductive wire and an other wire is on the drop. With a voltmeter ...
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69 views

How does one optimize the molar concentration of electrolyte in terms of the rate of electrolysis?

There are many textbooks/recipes for various electrolyte solutions in the electrolysis of water. I know there is a minimum voltage to kick off electrolysis, and I'm supposing a minimum concentration ...
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1k views

Calculating Electrode Potential for Electrolytic Cell at Non-Standard States

Recently, I came across an interesting question that left me rather baffled. I was asked to calculate the minimum voltage required for the electrolysis of 1.0 M of NaCl in neutral solution using the ...
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207 views

What is the Gibbs Free Energy in Zinc Electroplating?

In zinc electroplating process, where zinc metal (anode) is deposited on an iron plate (cathode), there is no net equation. Then why do we need to apply voltage to the system to produce zinc metal on ...
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374 views

Reverse single replacement reaction

Is it possible using electrochemistry or some other method to reverse a typical single replacement reaction to go in the opposite direction. For example, is it possible to take silver metal and ...
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96 views

Why does copper and zinc connected by a wire in 6.0M NaOH become a galvanic cell?

For an experiment I placed two electrodes of copper and zinc connected by a wire in 6.0M NaOH. According to standard reduction potentials, there should be no reaction; however, the copper becomes ...
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87 views

The potential range of the cyclic voltammetry of CoCat in KPi made of D2O

I have a phosphate buffer adjusted to pH 7, and another phosphate buffer made of deuterium oxide (D2O) adjusted to pH 6.6 (pD 7). I want to conduct cyclic voltammetry of cobalt oxide catalyst in these ...
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45 views

How long does it take to turn aluminum smelters on and off?

This may fit better under "engineering," but I figured I'd start here. Aluminum is produced through an electrolysis process, and Wikipedia tells me that the electrolytic cells need constant power in ...
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597 views

Junction Potential at Each End of a Salt Bridge

I am having trouble with the concept of a junction potential as it relates to the salt bridge of an electrochemical cell. I understand that a junction potential occurs between two solutions of ...
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66 views

Hot-side and Cold-side rechargeable chemical compound

I am wondering if such a chemical/material exists which, upon triggering, becomes cold on one side and hot on the other in which after all the chemical bonds are broken/built (however it would work), ...
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400 views

Hydrogen Peroxide - Iron Nail Galvanic Cell?

I am planning to create a simple galvanic cell made up of common household materials. Suppose I have hydrogen peroxide (to serve as cathode), diluted in water, in one beaker, and I have a bunch of ...
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84 views

Calculating current for electrolysis process

Is there a way to calculate the current during electrolysis of a dilute NaCl solution. I need to oxidise the chloride ions to create hypochlorite ($\ce{OCl-}$), so I was thinking of using 2 inert ...
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49 views

Addition of anodes and cathodes in electrolysis

I am doing a research on the production of hypochlorite through an electrochemical cell using a brine feed. I know that using using an undivided cell would allow for the chlorine atoms that was ...
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159 views

Resistivity of pure water vs salt water for electrolysis

OK so I have a group project. Were "building" an ammonia plant. Part of the plan is to gather the $\ce{H2}$ we need from the splitting of pure water. We've been told $1000\ \mathrm{kg}$ of $\ce{NH3}$ ...
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92 views

Does aluminium (III) react with copper?

We all know know that Aluminium react with cupric producing Copper and Aluminium (III), but does Aluminium (III) react with Copper?
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270 views

Galvanic cell of copper and zinc

When we dip zinc metal in zinc sulfate solution, does zinc sulfate ionize into Zn and sulfate ions? Zinc ions come into the solution as Zn$^{+2}$ so why is the metal not completely dissociated? Why ...
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2k views

Trends in conductivity in groups 1 and 2

I have read that the trend for conductivity in groups 1 and 2 is a decrease down the groups (generally). Apparently this is because the atoms of each element get larger, so while the number of ...
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573 views

How to determine concentration of salt in a salt bridge

How do you determine as to what concentration of solution you need for a salt bridge in a galvanic cell? Do you even need a specific concentration in the first place?
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166 views

how a galvanic cell works with a different metal cation in electrolyte than used in electrode

A traditional galvanic uses zinc as the anode electrode submerged in a zinc sulfate electrolyte, and copper as the cathode electrode submerged in a a copper sulfate electrolyte. I wanted to know what ...
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256 views

Reduced Graphene Oxide (RGO) Conductivity vs Everything Else

Reduced Graphene Oxide (RGO), is the reduced version of Graphene Oxide (GO). Both RGO & GO are easily manufactured when compared to the complex process used to manufacture the 'atom-thick' ...
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991 views

Difference between using Zinc Nitrate instead of Potassium Nitrate for Salt Bridge Solution?

I have a lab question which asks "Suppose that before you began this experiment you ran out of your salt bridge solution of Potassium Nitrate and the only substitute available was zinc nitrate, would ...

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