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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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Electro chemistry [on hold]

Find the value of the emf of the following battery at 25 ° C, specifying the polarities of the electrodes and writing the spontaneous global reaction:
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Electrochemistr— how does decreasing molarity of one half-cell solution affect cell potential [on hold]

For my electrochemistry project I decreased the molarity of one half-cell solution (which was the cathode), how does this affect the cell potential?
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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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1answer
659 views

Adding Standard Reduction Potentials

I am working the following USNCO problem (#41 from 2002). Based on this question and answer Deriving a reduction potential from two other reduction potentials, it seems that $\Delta G$ must be ...
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2answers
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How to determine the potential of a cadmium zinc cell under standard conditions?

I write the half-equations: \begin{align} \ce{Zn &<=> Zn^2+ + 2e^-}& E^\circ &= +0.763~\pu{V}\\ \ce{Cd^2+ + 2e- &<=> Cd}& E^\circ &= +0.403~\pu{V} \end{align} In ...
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1answer
60 views

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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Copper voltaic cell potential [on hold]

Copper electrodes are placed into two aqueous solutions of copper(II) sulfate at 25 °C. One compartment contains a 1.0 M solution while the other compartment contains a 0.10 M solution. The two ...
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Chemistry Olympiad Question [on hold]

Can someone explain how to do this? The answer is C. I know that the direction of electron flow is from the 0.1M to 1.0M end, but I dont know how to calculate the cell potential.
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1answer
2k views

Why does the Co³⁺/Co²⁺ couple have such a high reduction potential?

Cobalt is changing from $\mathrm{(3d)^6}$ to $\mathrm{(3d)^7}$ electronic configuration. What's so stabilizing about that? Just by reduction potentials this couple is more oxidising than hydrogen ...
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1answer
28 views

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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1answer
42k views

Does concentration of salt increase or decrease rate of rusting?

I want to know whether increasing the concentration of salt, specifically $\ce{NaCl}$, increases or decreases the rate of rusting. There are conflicting theories that explain opposite outcomes: ...
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14 views

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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25 views

How do you decide which half-equation to use? [closed]

In electrochemistry, half equations apparently do not have to be balanced when calculated E Standard Cell. But when a metal has several possible half equations, in different oxidation states, how do ...
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105 views

Why does chromium metal not react with a solution of Mg^2+ even though their standard cell potentials produce a net positive voltages?

Write net equations for the spontaneous redox reactions that occur during the following or NONE if there is no extensive reaction. Use the lowest possible coefficients. Include states-of-matter under ...
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0answers
3k views

Calculating Solubility Product of AgCl from electrode potential

I have to use a measured electrode potential to find the solubility product of $\ce{AgCl}$. In our experiment, we first mixed one drop of $\pu{1.0 M}$ $\ce{AgNO3}$ with $\pu{10 mL}$ of $\pu{1.0 M}$ $\...
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0answers
12 views

How to make a voltaic cell work? [closed]

i've been trying to build a voltaic pile for a better part of 2 weeks with no success. I've tried everything i can think of, but nothing seems to work. There are a couple reasons i suspect are the ...
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28 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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2answers
64 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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3answers
9k views

Is the 'n' in Delta G = -nFE, ever negative?

Is it possible for $n$ in $\Delta G=-nFE$ to ever be negative? Trying to figure out where I went wrong on some thing and want to rule that out.
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2answers
62 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 ...
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0answers
14 views

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
65 views

Is basic solution an electrode?

Question: Calculate the potential of hydrogen electrode in contact with a solution of pH 10. My attempt: Cell reaction: $\ce{ H^+ + e^- -> \frac{1}{2}H_2 }$ I've attempted to solve this ...
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1answer
176 views

Can gas be made to block radiation better?

Can any gas block radiation? I ask this because I would like to know if the properties of any gas element would chemically react differently with radiation from adding an electrical current. This ...
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2answers
52 views

Determination of solubility equilibrium using galvanic cell reactions

This is the problem: We can determine the solubility equilibrium for silver bromide using cell: Ag (s) | AgNO3 (aq) || KBr (aq) | AgBr (s) | Ag (s) We know that: $\text{AgBr} + \text{e}^- \...
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1answer
28 views

When surface area of electrodes is increased, why does the current in the galvanic cell increase?

I did a lab in galvanic cells where I changed the surface area. As a result, the current increased, but I don't really understand why. I guessed it was because more are means that more ions from the ...
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1answer
46 views

How to use Kohlrausch's law with ionic equivalent conductances? [closed]

My text says that for an ionic compound like AxByif ionic equivalent conductance of Ay+ is a and that of Bx- ion is b, then the equivalent conductance for AxBy would be a/y + b/x Now my question is:...
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1answer
35 views

Do the salt bridge ions have to match the ions in the half-cells solutions?

Does the salt bridge in a galvanic cell have to have the same ions as the ones in the solutions? E.g. does it need to have nitrate ions if the half-cells contain copper nitrate and zinc nitrate, or ...
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1answer
29 views

Measuring bioanode potential against Ag/AgCl reference electrode

I'm trying to make a bioanode for use in a microbial fuel cell. I have a piece of carbon cloth in an acetate solution with river sediment. I'd like to know the potential of the anode, so I connected ...
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1answer
33 views

How does a Pt and reference electrode measure the cell potential in a potentiometric titration?

I'm trying to perform a potentiometric titration to determine the redox potential of a $\ce{Fe^3+|Fe^2+}$ couple. To do this, I am using an $\ce{Ag|AgCl}$ electrode connected to an inert $\ce{Pt}$ ...
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0answers
18 views

Why do reference electrodes have porous frits or membranes as a salt bridge?

From what I understand, they act as a salt bridge between the reference electrode electrolyte and the analyte solution (in a potentiometric titration). But why do we use partially permeable membranes ...
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2answers
79 views

Is it possible to build a non-degrading battery?

I am not a chemist, nor do I know anything about chemistry. What I am interested in are batteries. I don't really care about the whole "Charge in minutes, last for days" types of batteries (the ...
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0answers
23 views

Instead of using an Ag/AgCl electrode, can I simply use another beaker and connect it to my solution via a salt bridge? [closed]

I'm trying to perform a potentiometric titration as part of my high school laboratory work, by reducing iron(III) to iron(II), and measuring the voltage change as I add cobalt(II) (to reduce it). The ...
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1answer
76 views

Electrosynthesis of HCl? [closed]

I was attempting to synthesize hydrochloric acid and it seems to have formed another form of chlorinated acid. The smell is more of chlorine and is extremely powerful. I got some on my jeans and it ...
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1answer
39 views

Why does electron flow from anode? [closed]

The above is a picture of Galvanic cell. Zinc anode is placed in Zinc sulfate solution so we have ions as Zn2+ and SO42-. On the cathode side we have the same situation we have Cu2+ and SO42-. My ...
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1answer
44 views

How does a change in the surface area of the electrodes affect the voltage produced by a galvanic cell?

I did a lab where I increased the surface area of the electrodes in a galvanic cell, that resulted in an increase in voltage. However, I have been reading and that is not supposed to happen. I am a ...
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0answers
30 views

Theoretical Calculations for Potential Generated in Salt Water Battery

I am using a $\pu{1.5 M}~\ce{KCl}$ solution as electrolyte and copper and aluminium electrodes but no salt bridge. So basically there is only one beaker with the two electrodes in it with the $\pu{1.5 ...
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22 views

Cause of imaginary part of Warburg element in EIS

In electrochemical impedance spectroscopy experiments (EIS) the diffusion of electroactive species at flat, macroscopic electrodes is commonly described by the Warburg element with the impedance ...
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36 views

Why V³⁺/V²⁺ couple has low reduction potential?

$\ce{V^2+}$ ion is more stable than $\ce{V^3+}$ because of the half-filled $\mathrm{t_{2g}}$ level. So, shouldn't the reduction potential be high?
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1answer
25 views

Which reactions occur during the oxidation and dissolution of bromide/bromine?

I'm trying to understand the fate of bromide anions during and after they undergo anodic oxidation. I have a solution of 94% DMF/6% water (by volume) with 0.1 M tetrabutylammonium bromide (TBAB) as ...
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2answers
49 views

How Can I Induce Corrosion Electrochemically?

I'm very interested in measuring corrosion in metal alloys, particularly in salt solutions. I understand metals corrode over time, however, I was wondering if it's possible to electrochemically "speed ...
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0answers
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Existence of single ion activities

I have used Davies equation to find what I believed was single ion activities and multiplied them on concentrations to define the thermodynamic dissociation constants for any kind of buffer to find ...
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1answer
197 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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1answer
8k views

How would using different salts in a salt bridge effect the voltage generated by a voltaic cell?

If I use a range of different nitrate solutions (e.g. calcium nitrate, iron nitrate) for the salt bridge in a voltaic cell, what effect would it have on the flow of ions in the voltaic cells? Will ...
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0answers
37 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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4answers
257 views

Is there any electronic component to water conductivity?

Answers to Decrease in temperature of a aqueous salt solution decreases conductivity indicate that the electrical conductivity of salt solutions arises from the mobility of ionic species and therefore ...
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2answers
57 views

What happens if I draw too much current from a home made battery?

If I try to make a battery like one of these: https://www.wikihow.com/Make-a-Homemade-Battery And then I short the two terminals, what will happen? Disregarding anything getting hot and burning up, I'...
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3answers
9k views

What is the freezing point of sulfuric battery acid?

As we all know, the freezing point of absolute sulfuric acid is 10 °C. The average lead-acid battery (sulfuric) uses ~30% sulfuric acid, and has a freezing point much lower than 10 °C. What ...
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3answers
715 views

Why does a complete discharge destroy a Li-Ion-Battery?

I read that completely discharging a Lithium Ion Battery is a very bad idea because it will lose plenty of capacity. But why? I know that the reaction (fot the LiFePO4 battery) is: $$ \ce{LiFePO4 + ...
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1answer
20 views

Is the Gibbs energy of bulk metals in a Daniell cell affected by temperature? [closed]

From literature values, it is implied that the change in Gibbs energy of a Cu-Zn voltaic cell is largely due to the difference in Gibbs energy of the bulk metals (solid Cu and solid Zn). Does ...
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1answer
29 views

Is the equation below for Gibbs energy only applicable under standard conditions?

This is quite confusing to me because it seems as if a lot of people use standard state equations and non standard state ones interchangeably: $$ΔG^\circ = -nFE^\circ$$