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
31 views

How the electrolyte help for oxidation and reduction process?

In a cell, There are two main parts namely : Electrode Anode Cathode Electrolyte We can take the half reaction at the Cathode. When the current flow from Anode to cathode there is a reduction ...
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2answers
57 views

How can I add more electrons to copper? [closed]

In a galvanic cell, there are two reactions taking place. One is oxidation and other one is reduction. The reduction reaction is $\ce{Cu^2+ + 2 e- -> Cu}$. In this reaction, the copper 2+ ion ...
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1answer
37 views

What is the relationship between concentration and voltage in a galvanic cell? How do you calculate the theoretical?

I am a year 12 Chemistry student and I was wondering if you could help me with some questions I have about a Galvanic cell experiment? I am doing an experimental report in Chemistry. The experiment I ...
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1answer
29 views

How can there be concentration and pressure terms simultaneously in the Nernst equation?

In the Nernst equation we are taught that the reaction quotient can have pressure terms and concentration terms simultaneously. According to my knowledge this does not happen anywhere else, so why can ...
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Charge and Discharge of a Battery [closed]

I'm a student who majors Chemical Engineering. I just have a question shown as below. First of all, I don't understand the answers of both 1) and 2). In my opinion, the answers should be switched. ...
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39 views

Free electrons of the wire in a galvanic cell [closed]

In a galvanic cell, do the free electrons contained inside of the conductive wire actually flow since a voltage is created across the wire, or is it just the electrons produced by the redox reaction? ...
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1answer
20 views

Controlling Current Density in Electrowinning Cell

What are the parameters which govern the current density in an electrowinning cell? What equations relate Current Density to the applied potential difference? Is it simply just Ohm’s Law J = σE? ...
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27 views

What is the activation energy of a Daniell cell?

I'm having trouble finding a posted literature value for the activation energy for the Daniell cell redox reaction: $$\ce{Cu^2+ + Zn -> Cu + Zn^2+}$$ Where might I be able to find this ...
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42 views

Does electrified water really kill germs? [closed]

I have a question. I want to ask a professional from out side of the company where my boss bought our cleaning supplies. Our school district was using a powerful disinfectant called Juvinall. Worked ...
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12 views

Why does my CA data suggest non-diffusion control but CC suggests diffusion control?

I've run chronoamperometric and chronocoulometric measurements on a ferricyanide/ferrocyanide redox couple in water and KNO3. My graph from CC appears linear which is consistent with the Cottrell ...
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1answer
67 views

How can sodium be reduced in the Castner–Kellner process?

In the Castner–Kellner process, why is sodium amalgam formed instead of hydrogen gas at the cathode? If we electrolyse brine solution, then it will liberate hydrogen at cathode, not sodium, because $\...
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1answer
23 views

Molten lithium carbonate conductivity

Does anyone know or could make an educated guess as to the conductivity/resistivity of molten lithium carbonate? Ideally, around 750 degrees C.
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Electrical conductivity and the limits of Kohlrausch's law

I am currently writing a lab report on electrical conductance and I realized that my partner prepared $\pu{0.1 M}$ solution instead of $\pu{0.01 M}$. Now, I am supposed to find the molar conductivity ...
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2answers
45 views

What is electrolytic protection?

My highschool textbook tells me that sacrificial protection (more technically-cathodic protection) and electrolytic protection are different. I have searched high and low for an explanation of ...
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2answers
39 views

How can I eliminate the harmful gas produced from the heating/manipulation of galvanized steel? [closed]

When welding on steel with a galvanized coating, hexavalent chromium is yielded from the chemical reaction. This gas is something that I would like to eliminate before I begin welding, possibly with ...
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1answer
53 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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1answer
58 views

Why is the voltage produced by a voltaic cell affected by temperature as described by the Nernst Equation?

I understand why changing the concentrations of the electrolytes in a voltaic cell affects the voltage. Given a zinc-copper cell for example, if I were to increase the concentration of the zinc ...
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1answer
41 views

Setup for Sensing change in concentration of NaCl

I am making a sensor to sense the change in concentration of NaCl. My background is in electronics and chemistry is not my strong area. I got some screen printed electrodes, with Silver (Working ...
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1answer
29 views

Predicting directions of redox reactions [closed]

Hello! In this textbook example question, how come the chlorine reaction, which has the greatest reducing power will not react? If it has the greatest E of 1.36 V that means it has most reducing ...
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1answer
46 views

Why are dendrites formed during dilute CuSO4 electrolysis black?

During the weekend, I wanted to conduct a kid's experiment - the copper dendrite formation. I was (partially) successful and now I would like to know what went wrong. The procedure was taken from the ...
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1answer
43 views

How does Fe2+ become Fe in sacrificial protection? [closed]

I've searched low and high on the internet, but nothing to help me. I know that zinc is oxidised in preference to iron, and that it "donates" those two electrons to iron. $$\ce{Zn -> Zn^2+ + 2e-}$$...
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1answer
26 views

Electrochemistry - Understanding Diffusion Potential

I have a big problem trying to wrap my head around this for several hours and I cannot seem to make sense of it. I have to link this scheme with the 3 colored potential profiles on the bottom of the ...
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1answer
42 views

Applied Potential and Electrochemical Cell Potential

Electrolysis of molten lithium hydroxide at $\pu{750 K}$ to form lithium metal $$\ce{4 LiOH -> 4 Li + 2 H2O + O2}.$$ Electrolysis will only proceed at an appreciable rate when the applied ...
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43 views

Find pH and Kw for water with given values of conductivity

At $\pu{25 ^\circ C}$, $\lambda_\infty (\ce{H+}) = \pu{3.5 \times 10^{-2} S m2 mol-1}$ and $\lambda_\infty (\ce{OH-}) = \pu{2 \times 10^{-2} S m2 mol-1}$. Determine $\mathrm{pH}$ and $K_\mathrm{w}$. ...
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Is anode actually ever negative?

Disclaimer: This question comes from a physics student. I was studying electrostatics and I was wondering how to charge a conductor at home without any fancy furs etc. So an idea came to me: take a ...
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2answers
68 views

Copper electrode in a Daniel cell

Suppose I have a beaker containing $\ce{CuSO4}$ solution and I dip $\ce{Cu}$ rod in it. What reactions are going to take place? Is the $\ce{Cu}$ rod going to acquire any positive charge? I am asking ...
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Why does changing the salt of the salt bridge effect the voltage produced in a galvanic cell?

My experiments results showed that the voltage decreases down $\pu{Group 1}$: $\ce{Cl-}$ salts in the salt bridge. All other variables were kept constant. $\ce{Zn}$ and $\ce{Cu}$ rods were used. ...
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37 views

Galvanic Cell Temperature Dependence

I'm currently studying the temperature dependence of the following cell: $\ce{Cu_{(s)} + 2Ag^{+}_{(aq)} <=> 2Ag_{(s)} + Cu^{2+}_{(aq)}}$ ($E^⦵ = \pu{+0.46 V}$) Experimentally, I recorded the ...
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1answer
37 views

electrochemistry experiment

something strange. i made an electrochemistry experiment in which i have measured the potential of cell: Ag, AgCl | (1M)KCl ║ [Fe(CN)6] 3-, [Fe(CN)6] 4- | Pt with different concentrations of Fe+2/Fe+...
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What is the yellow compound formed in electrolysis of brine?

Last week, I tried to conduct electrolysis of brine in my house using copper electrodes and 6V battery. After sometime, the entire solution turned orange/yellow. The yellow substance formed a kind of ...
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1answer
22 views

How are cells rechargable?

I have learnt that you can test if a reaction is thermodynamically feasible by testing if the cell voltage $E_\mathrm{cell}$ is greater than $0$. Surely, if a reaction is feasible, then the $E_\mathrm{...
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1answer
27 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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1answer
34 views

Electrolysis of Baking Soda separated by semi permeable membrane

I have dissolved baking soda in battery water (de-ionized), in a glass beaker and used a food handling glove (vinyl) as a semi-permeable membrane to separate a graphite electrode from a copper ...
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How can you have a reduction potential for a non redox reaction?

The standard reduction potential for the half cell $$\ce{FeCO3_{(s)} + 2e- <=> Fe_{(s)} + CO3^2-} \quad\quad(E^o =-0.756 \text{V})$$ and the standard reduction potential for the half cell $$\ce{...
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Oxidative phosphorylation analogue

Does the salt bridge in galvanic cells resemble the ATP pump in the inner mitochondrial membrane? And if yes than did someone use this pH difference in harvesting this energy?
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1answer
27 views

Reduce potential by adding NaOH. With solubility

Ff I don’t know how to calculate c part.. What I did is: E=E* - RT/nF lnQ Ks(cuoh2) = [cu][oh]^2 So we can know how much concentration of cu has to be eliminated and with that we can calculate the ...
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2answers
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clarification on background limits in electrochemistry

I’m teaching myself electrochemistry, and this question is from the general introduction of the book I’m using. According to Bard’s Electrochemical Methods book, in a given cell, the background limits ...
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3answers
71 views

Why is this reaction spontaneous in standard conditions?

To study if this reaction is spontaneous I proceed in this way: $$\ce{2H_{3}O^{+} +Fe ->H_{2} +Fe^{2+} + 2H_{2}O}$$ First I write the two semireaction: $$reduction: \ \ \ce{2H_{3}O^{+} +2e^{-} ->...
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1answer
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How does increasing the Hydrogen Concentration of CuSO4 (electrolyte) affect electroplating of copper

I'm trying to find an answer as to how lowering the pH of the CuSO4 solution during electroplating of copper affects the amount of copper deposited onto the cathode. My very basic understanding is ...
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1answer
45 views

Why oxidation potential of an electrode equals negative reduction potential of the same electrode?

My textbook states that: $E^\circ_\mathrm{ox} = -E^\circ_\mathrm{red}$ (of same electrode) I know that electrons flow from anode half cell (oxidation) to cathode half cell (reduction). But if $E^\...
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Competing half reactions in electrolysis of aqueous solution of sodium hydroxide

If you run a direct current using pure nickel electrodes through a solution of NaOH in distilled water, you will separate the water into hydrogen and oxygen. Are there any other reactions that could ...
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2answers
28 views

Way to confirm dichromate ion presence where other ions are messing with the color

I'm currently working on an electrolytic setting where a stainless steel (430 series, mainly made of iron and chromium, but no nickel) anode is dissolved in acidic environment (sulfuric and phosphoric ...
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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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Confusion regarding the positively charged copper electrode in a Daniell cell [closed]

Suppose I bought a newly manufactured Daniell cell then in this situation, can someone explain what all will be going on at the zinc and copper electrode? (Since it is newly manufactured and not used ...
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Greater ligand stabilization of the lower oxidation state increasing redox potential

According to Atkins, P.W., De Paula, J. and Keeler, J., 2006, Atkins' Physical Chemistry, $$ \begin{align} \ce{[Fe(CN)6]^3- + e- &<=> [Fe(CN)6]^4-} &\quad E^\circ &= \pu{+0.36 V} \...
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1answer
38 views

Keeping Li-Ion battery on charger vs. plug the charger in and out regularly

I have read on numerous occasions a set of recommendations to keep a Li-Ion battery happy: avoid discharging the device at all costs, don't charge it up completely, keep it as much as possible between ...
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3answers
137 views

Electrochemistry conditions for voltage to increase in a galvanic cell

I understand that increasing the concentration of reactants in a galvanic cell generally causes the voltage of the cell to increase. But is that really the case always? Consider a standard cell of ...
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1answer
71 views

Why does the rusting process start from the bent/squeezed portion of iron?

I have noticed that the rusting of iron starts from the squeezed or bent parts of iron piece. I want to know what is the peculiar reason for the observation that rusting starts from bent or irregular ...
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How to calculate the energy required for an electrochemical reaction with over potential?

I am particularly interested in the reaction described in High‐Selectivity Electrochemical Conversion of CO2 to Ethanol using a Copper Nanoparticle/N‐Doped Graphene Electrode. The reaction is $$ \ce{...
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1answer
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how can I measure the pH of a HF:H2O:CH3OH solution? [closed]

how can I measure the pH of a HF:H2O:CH3OH solution? more specifically, how can I precisely and accurately measure the H+ ion concentration?

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