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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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Replacing Salt Bridge with Platinum Sheet

What would happen, if in a galvanic cell, the salt bridge is replaced by an inert platinum sheet? Would charges accumulate on the sheet? Would the cell still work, and produce less emf than earlier, ...
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How to calculate Ksp from concentration cell equation of Ag2CrO4 [on hold]

For the following cell Ag-Ag+(saturated Ag2CrO4) // Ag+(0.125 M) - Ag E(cell) = 0.183V Ksp (Ag2CrO4)= y × 10^-12 What Is value of y
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In an electrochemical cell with a high resitance voltmeter, why is a salt bridge used?

Because if the high resistance voltmeter prevents the movement of electrons, why would there be a need of a salt bridge to neutralise the charge? Also, without the salt bridge, why would the ...
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28 views

Regarding Standard Electrode Potentials

If the standard hydrogen electrode (SHE) is set arbitrarily to have a potential that is equal to 0 V, and has an absolute real potential. Then, in electrochemistry, how are the electrode potentials of ...
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Polarity of Cell Electrodes [duplicate]

I understand that the anode in a galvanic/voltaic cell is considered to be 'negative' while the cathode is 'positive'. However, in an electrolytic cell, the cathode is 'positive' while the anode is '...
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Does the anode become negative?

Electrolysis: If anions continue to deposit electrons on the anode, does this mean after a while the anode becomes negative? If not how is the anode discharged from it’s electrons
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Does reduction/ oxidation take place separately at a half cell electrode?

In the redox reaction chapter, we learn that oxidation and reduction go hand in hand. The oxidising agent oxidises by accepting the electron released by the reducing agent and gets reduced in the ...
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30 views

Can static electricity damage solar cells?

How does static electricity damage common solar cells making them less photo reactive? At watt voltage and/or amps would change the chemistry of the common solar cell? I want to think that as long ...
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183 views

Electrolysis of water: Which equations to use? (IB Chem)

There is a list of standard electrode potentials at 298 K from the p. 23 of IB Data Booklet 2016. Which of the following equations (forward/backward reactions), from the two possible ones involving ...
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Charge phone using simple voltaic cell [closed]

Can i charge my phone using voltaic.cell and. How because i have cut the usb wire and found 4 wire in it which is red,black,green,white which one is connected to mg and which one is connect to copper
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What defines a discharged battery?

In the case of an AA Alkaline battery, what actually happens inside the battery once it is fully discharged? What components of the battery change as we use it?
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Where does copper form?

I thought zn and cu both lose 2e- to pt but someone is telling me it's wrong]
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Why is reduction potential of water ( 2H₂O + 2e⁻ → H₂ + 2OH⁻ ) is -0.83 insted of 0, as in the case of (2H⁺ → H₂)?

I came across this value of reduction potential of water while solving a question. Also, I noticed that, for example $$\ce{Ag+ → Ag}$$ has a fixed standard potential, and the same is used when we do ...
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Still taught to reverse oxidation half cells in electrochemistry?

In a question, Oxidation of metals/halogens by oxygen gas in acidic aqueous solution, there was a point made that reduction half-cells should not be reversed. I was taught ($\approx 1970$) in the ...
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Oxidation of metals/halogens by oxygen gas in acidic aqueous solution

I had some confusion about the correct answer to the following question: Which substance can be oxidized by $\ce{O2(g)}$ in acidic aqueous solution? Two of the answer choices were metal cations (...
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1answer
27 views

Metal that does not deposit silver (Ag)

Hi Chemistry enthusiasts! I am working on my scholarship exam practice but I am considered myself as a newbie so I would like to hear your opinion :) From (1)-(4) below choose the metal that does ...
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Calculate chemical potentials to find electrode Fermi level

I'm running some simple simulations of the semiconductor-electrolyte interface and I'm having a hard time figuring out the equilibrium condition. Can someone please help me with my electrochemical ...
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3answers
60 views

What is the flow of electrons, cations, and anions in a voltaic cell (please see image attached)?

This is an IB question. The mark scheme says that the correct answer is A and only A. But I believe B is also correct. The following is my thought process. Since A is more reactive, it undergoes ...
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2answers
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For Hess' law type questions, when do you take the inverse of the constant and when do you switch the sign?

For example, when you're given the enthalpy $\Delta H$ of a reaction and you want to switch that reaction around in order to add it to something else, you switch the sign. Furthermore, when adding ...
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[Co(H2O)6]3+ vs [Co(NH3)6]3+ oxidising water

Cobalt(III) complexes cannot be prepared by addition of the ligand to a solution of the metal cation because the aqua cation $\ce{[Co(H2O)6]^3+}$ has no stable existence in solution. It is strongly ...
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23 views

Would electrolysis work with a conductive (but waterproof) divider between anode and cathode?

Note I am not trying to "double fuel efficiency" in a car or something scamey like that. My purpose is to fill balloons with hydrogen and possibly power an HHO torch (also make it safer because pure ...
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What do electrons usually do when lead acid battery is idle?

Lead acid batteries operation are governed by Redox reactions for charging and discharging. But, what do electrons usually do when lead acid battery is idle? And why? Assumptions: Say more ...
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Reduction Potentials [closed]

Standard electrode potential values can be used to judge the reducing ability of a metal. When I was introduced to this topic a simple picture was painted: you put a metal into a solution of its ions. ...
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3answers
67 views

Confusion on electrode potentials

Standard electrode potential values can be used to judge the reducing ability of a metal. When I was introduced to this topic a simple picture was painted: you put a metal into a solution of its ions. ...
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1answer
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What are the products in the reaction of sulphuric acid and Group 2 metals?

When group 2 metals, says magnesium, is reacted with nitric acid, oxide of nitrogen is produced beside hydrogen gas. The standard electrode potential values agree with this: $$ \begin{align} \ce{Mg^...
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What is the ideal temperature and pressure to crack water?

Using sun mirrors and solar cells for electricity. What temperature, pressure and voltage ideal for cracking water. Source: NPR Source Would it take more or less electricity to crack water under ...
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What is the reasoning behind deriving electrode potential of a metal-metal sparingly soluble salt electrode?

Considering a sparingly soluble salt $M_xN_y$ of the metal $M$, in which the corresponding reaction is $M_xN_y$ = $xM^{y+}$ + $yN^{x-}$, the standard electrode potential is given by $E^{o}_{M_xN_y/M/...
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Does increasing the concentration of the anode electrolyte in a galvanic cell increase or decrease the voltage produced

Im in kind of a pickle here. I am using nernst equations to calculate the theoretical voltage produced for different concentrations of $\ce{Al(NO3)3}$. Reaction: $$\ce{2Al(s) + 3Pb^{2+}(aq)⟶2Al^{3+}(...
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Why do electrocatalysts based on polyoxometalates and carbon materials have a weaker activity/performance in acidic media?

I am testing now some doped N and S doped carbon nanomaterials alone and immobilized in POM for the purpose of developing a nanocomposite that can serve as an electrocatalyst for energy-related ...
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What are the reasons that make platinum a good electrocatalyst for oxygen reduction reaction? [duplicate]

Researchers are trying to find new electrocatalysts for energy related reactions in fuel cells in order to replace the expensive platinum-based materials. I would like to know what are exactly the ...
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1answer
169 views

Does higher Oxidation/ reduction potential translate to higher energy storage in battery?

Some articles refer to the fact that Lithium is preferred metal of choice for batteries because their half cell voltage is high (slightly above 3V) If that is the case why can't we use other metals ...
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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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Intensive and Extensive Properties--Resistance

Is resistance an intensive quantity or an extensive one? And why? Let me present 2 scenarios. Resistance of a wire: The resistance of a wire depends on area and length. This implies it depends on the ...
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Where does Free Energy go in a Redox Reaction?

This doubt came to my mind while answering the following question: Why does a voltaic cell not operate unless the two separate compartments are connected by an external circuit? The answer seems ...
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3answers
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No sign flipping while figuring out the emf of voltaic cell?

I learnt that for a voltaic cell, the value for the $E_\text{cell}^\circ$ when the reaction is spontaneous is given by $$E_\text{cell}^\circ = E_\text{cathode}^\circ - E_\text{anode}^\circ, \label{...
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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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Oxidation states of Cu in YBa2Cu3O6 based on crystal structure [duplicate]

How does on go about this? I understand There is a +5 charge distributed on 3 copper ions. So either we have 2+, 2+ and 1+ or 3+, 1+, and 1+. Judging from the structure there are to unequivalent types ...
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Can gold cause tin or other metals to corrode?

I stumbled upon the following article while trying to identify some old RAM modules: https://www.techrepublic.com/article/quickly-identify-ram-chips-with-these-tips/ In the article, it mentions the ...
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Why does increasing the concentration of oxidizing agent decrease the E° in a galvanic cell?

In a galvanic cell, when we add ions of the oxidation agent (in this example, Zn2+) to the anode solution, it decreases the cell potential. However, if the Zn2+ ions aren't involved in the redox ...
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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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Which ions determine ionic conductivity of a salt solution?

Let's take $\ce{ZnSO4}$ salt solution in water for example. So the ions inside my solution will be $\ce{H+}$, $\ce{OH-}$, $\ce{Zn^2+}$ and $\ce{SO4^2-}$. My questions are: Is the ionic conductivity ...
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What happens electrochemically when bird droppings corrode cars?

I think the metal of the car first goes through an acid corrosion, followed by an electrochemical corrosion. First, the uric acid in bird poop corrodes with iron: 2Fe+C5H4N4O3 -> C5N4O3Fe2+2H2. Then, ...
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1answer
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Pressure-dependence of electrolysis voltage [closed]

I'm trying to better understand electro-chemistry, so please explain why this second-kind perpetual motion device won't work. I guess it's safe to assume it won't work one way or another. There is a ...
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Can CO2 Be Electrochemically Reduced to Carbon Nanotubes?

Mitigation of CO2 as greenhouse gas has driven increasing investigation of its chemical reduction. The 2018 paper "Recent Progress in the Theoretical Investigation of Electrocatalytic Reduction of CO2"...
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Solutions when Electroplating

I'm essentially conducting an experiment to see whether using different copper-based compounds when electroplating copper onto an iron nail would give different results. So far, I've used copper ...
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51 views

How to calculate the cell potential after the reaction has operated long enough for the Fe2+ to have changed by some concentration?

Consider the cell described below at $\pu{261 K}$: $$\ce{Fe | Fe^2+ (\pu{0.925 M}) || Cd^2+ (\pu{0.981 M}) | Cd}$$ Given $E^\circ_\ce{Cd^2+ -> Cd} = \pu{-0.403 V}$, $E^\circ_\ce{Fe^2+ -&...
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Determining the reduction potential of a half cell reaction at a given pH

$E^\circ_\ce{Cu^2+|Cu} = \pu{0.34 V}$. What will be reduction potential at $\mathrm{pH} = 14$ for the same couple? Given that $K_\mathrm{sp}$ of $\ce{Cu(OH)2}$ is $10^{-19}$. My Attempt I think ...
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1answer
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Cobalt electroplating over nickel-plated steel

From my research, I understand that cobalt can be used on top of a nickel layer to improve durability of the nickel plating on a steel object. I am using a nickel anode and nickel acetate as ...
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Difference between electrode potential and standard electrode potential

I was studying electrochemistry but the thing that confused me was that what is the basic difference between electrode potential and standard electrode potential?
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2answers
71 views

No current in homemade galvanic cell

I built a galvanic cell using 0.01 M solutions of copper sulfate and zinc sulfate. I used copper and zinc electrodes and immersed them into the proper solutions (copper into copper sulfate, zinc into ...