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).

Filter by
Sorted by
Tagged with
-2
votes
1answer
24 views

If all the points on my graph fit on a logarithmic and polynomial trend line, how do i justify which trend line i should use? [closed]

My graph is mass of deposit vs concentration. The mass of deposit increases with concentration.
-5
votes
1answer
33 views

Which is a better electrolyte for electroplating copper? [closed]

I need to know which is a better electrolyte to use when electroplating copper: copper sulfate or copper nitrate?
2
votes
0answers
18 views

Can I use an electrolyte containing a different cation from the anode when doing an electroplating experiment?

For example, I want to purify copper. So the anode will be impure copper and cathode will be pure copper. However, instead of using copper sulphate/halides/nitrate solution, can I use magnesium ...
0
votes
0answers
18 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) ...
2
votes
3answers
75 views

Does anyone know a database that shows the effect of electrolyte concentration on the production of hydrogen gas during electrolysis of water?

I'm currently studying in the International Baccalaureate model. This high school model asks their students to do an individual work called the Internal Assessment. One of the subjects I study is ...
0
votes
1answer
35 views

Redox flow battery [closed]

What is meant by decoupling of power and energy in context of redox flow battery? I understand that the electrolyte containing the active ions can be stored in tanks and that adds flexibility in scale ...
-1
votes
2answers
34 views

How do the two half cells of Daniel cell know when they are connected?

I'm currently studying electrochemistry in school, and there is something I don't can't quite understand about Daniel cell. When you put $\ce{Zn}$ solid into $\ce{ZnSO4}$ solution, does the electrode ...
0
votes
1answer
27 views

Solution for Electroplating Selenium?

I need to electroplate selenium onto a conductive metal (for an experiment). The end goal is a thin film of pure, elemental selenium. Unfortunately I can't find anything on the internet: Ideally, I'd ...
0
votes
3answers
68 views

Balancing redox equations with oxygens in multiple oxidation states

How do you balance this using the ion-electron method; $\ce{CrO5 + H2SO4 -> Cr2(SO4)3 + H2O + O2}$ The oxygen has multiple oxidation states in $\ce{CrO5}$, and none of the sites I looked this up ...
0
votes
1answer
41 views

Electrolysis of copper without any copper initially in solution

Let's say we have two copper electrodes as shown in the image, and there is a solution with copper nitrate. In this case, I know that copper will deposit onto the cathode and copper from the anode ...
0
votes
1answer
40 views

Why does increasing the concentration of the salt bridge in a galvanic/voltaic cell increase voltage?

I recently set up an experiment with 1M half cells made up of zinc and copper nitrate. They were connected with a sodium nitrate salt bridge of varying concentrations. As the concentration doubled 5 ...
3
votes
1answer
55 views

How to deal with the unit “Coulomb per equivalent”? [duplicate]

In a question that I came across they defined $1\,\pu{F}$ as 96500 coulomb per equivalent. Now as far as my knowledge is concerned $1\,\pu{F} = 96500\,\pu{C/mol}$. The question involved asks to ...
1
vote
2answers
48 views

Why does the oxidizing strength of the chlorates decrease with increasing oxidation number?

Here is a table of the standard reduction potentials of the chlorates from wikipedia: Intuitively, one would expect that the more positive the oxidation state, the more oxidizing that compound would ...
-1
votes
2answers
24 views

Why is the ionic product of water $K_w$ the same in acid, water, and alkali?

Seen on the web: The concentration of [H+] and [OH−] both vary based on the the composition (acid/alkaline) of the solution, but the remarkable thing is that their product does not. When [H+] goes ...
-1
votes
1answer
37 views

Copper (II) Acetate from 5% vinegar + salt, electrochemically

I'm trying to create Copper (II) Acetate crystals, but in these times of Coronavirus it's difficult to come by hydrogen peroxide. I could be patient, but I'm not, so I'm trying to make it ...
-1
votes
2answers
108 views

Is there a quick way to approximate a logarithm in Nernst equation?

The problem is as follows: In a galvanic cell the cathode is an $Ag^{+}(1.00\,M)/Ag_{(s)}$ half-cell. The anode is a standard hydrogen electrode immersed in a buffer solution containing $0.10\,...
2
votes
1answer
45 views

Electrode potentials vs interfacial potential differences

Between an electrode and an electrolyte there exists an interfacial potential difference. Many authors give the electrode potential to be the electric potential of the electrode relative to the ...
1
vote
2answers
43 views

Why is Electrochemistry often the method of choice for determining Ksp values? [closed]

I don't understand the relationship they have with one another. Please, someone explain.
1
vote
1answer
77 views

Limiting molar conductivity of multiple solutes

Suppose there is a water solution at $\pu{25 °C}$ with $\ce{Na+},$ $\ce{Mg^2+}$ cations and $\ce{Cl-},$ $\ce{HCO3-}$ anions. Concentrations $[\ce{Na+}],$ $[\ce{Mg^2+}],$ $[\ce{Cl^-}]$ and $[\ce{HCO3-}]...
1
vote
0answers
26 views

What is the electrolytic bath used in gold-plating of copper articles?

The answer is $AuCl_3 + NaCN$ Now I understand that for electroplating, we need gold to be deposited on the copper article, and the electrolyte must enable that deposition. But I don’t know what is ...
2
votes
1answer
96 views

Does the order of a written redox couple matter?

My understanding is that a redox couple is an unordered pair of two conjugate species. So we could speak of the redox couple consisting of $Ag$ and $Ag^+$; depending on whether a given redox couple is ...
-1
votes
0answers
14 views

Don't understand the formation of Li dendrites regarding Sand's Time

I have a question about Sand' time which can indicate the start of the formation of lithium dendrites. From the paper I'm reading, it defines the concentration gradient in a cell as below. And, ...
-1
votes
1answer
56 views

Most understandable notation for reduction and oxidation potentials

Nowadays a lot of electrochemistry is done using just electrode potentials (i.e. reduction potentials), so if in doubt the notation $E^o$ tends to imply a reduction potential. However, some chemists ...
3
votes
2answers
75 views

What is the hidden meaning of electrochemical stability window? [closed]

I don't really get the real meaning of the electrochemical stability window. I googled a lot, and the only thing I understand about the electrochemical stability window is that it's the voltage range ...
1
vote
0answers
16 views

Which is the best kind of filter papers to use to extract silicon nanoparticles after acid wash, hydeophobic or hydrophilic?

I'm looking for filter papers to extract silicon nanoparticles after acid etching. I found that much of my material is get wasted with my Whatman Grade 4 filter paper. I am thinking to use membrane ...
4
votes
2answers
332 views

Will galvanic corrosion happen on a ring made of gold and bronze?

I have recently got a custom-made ring from a jeweler. It’s made from a byzantine-period bronze ring enveloped in a gold bangle. The bronze ring is “glued” onto the gold ring through some kind of ...
1
vote
1answer
18 views

Reaction in Zinc-Carbon-Ammonium Chloride battery

I made a dry cell battery from zinc (Zn), carbon (C) and ammonium chloride (NH4Cl) which produced a current of 0.4 amps and voltage of 1.1V. However when I could not find the redox reaction that was ...
2
votes
1answer
249 views

Why do we write electrode potentials next to chemical reactions? [closed]

We might have a half cell consisting of the redox couple $\ce{Ag+}/\ce{Ag}$, which for example's sake might be fixed to be at the cathode (i.e. undergoing reduction). The reaction at the cathode is ...
0
votes
0answers
27 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 ...
-1
votes
0answers
24 views

Molecular mechanics of current flow in electrolysis of alkaline water - effect of electrolyte concentration?

I’m confused about the how to explain the effect of electrolyte concentration (eg. NaOH) on the magnitude of the current when an external voltage is applied. I want a precise explanation and not a ...
-3
votes
1answer
43 views

galvanic cell vs electrolysis [closed]

At school(high school), to calculate the voltage needed for electrolysis, we calculate the voltage produce if the elements were in a galvanic cell, preceded by a minus. So if a galvanic cell with Cu ...
-1
votes
0answers
28 views

What is the Gibbs free energy of Lithium-Graphite and Lithium Cobalt-Oxde

I'm trying to do some hand calculations for Lithium-Ion batteries and I can't seem to find the standard state Gibbs free energy of formation for either Lithium-Graphite or Lithium Cobalt-Oxide. They ...
0
votes
0answers
18 views

What determines the potential of a half-cell with chemically inert electrode in a solution containing more than one redox pair?

Let's assume we have an electrode made of an inert metal as platinum or gold immersed in a complex mixture containing many compounds (in various concentrations) that can undergo redox reactions. We ...
2
votes
1answer
58 views

Electrode potentials in a potentiostat

I am not a chemist but for a university project i am dealing with simulations concerning a potentiostat using a 3-electrode setup. For example in the book Electrochemical Methods (Bard & Faulkner,...
0
votes
0answers
56 views

Why is the equilibrium constant for a Daniell cell not equal 1?

Using the equation $$RT\ln K = nFE,$$ the equilibrium constant $K$ for a Daniell cell at standard conditions can be found as $$K = \exp\left(\frac{2 × 96500 × 1.1}{8.3145 × 298.15}\right) = \pu{1....
-1
votes
1answer
43 views

Since a Voltmeter does not account for the internal resistance of a voltaic cell, how can the actual EMF of the cell be measured?

Since a voltaic cell has some internal resistance the voltage measured by the voltmeter connecting the electrodes, is actually lower than the emf of the cell, so how can I measure the EMF of the cell ...
4
votes
1answer
77 views

Subtracting standard electrode potentials

As far as I'm aware, if we construct a half cell ($\ce{A + e- <=> A-}$) under standard conditions then the standard electrode potential $E^⦵$ is the potential of the $A/A^{+}$ couple wrt. SHE, ...
3
votes
1answer
396 views

Can the direction of electron flow in a voltaic cell be reversed? [closed]

I am wondering if the direction of electron flow in a voltaic cell be reversed such that the cathode becomes the anode and vice versa. I understand this is not possible for two standard half-cells, ...
2
votes
2answers
52 views

What exactly is the 'shuttle effect' in sulfur batteries?

Ref : https://www.electropages.com/blog/2020/01/why-lithium-sulphur-batteries-are-taking-so-long-be-used-commercially Because they continually shuttle between the electrodes, they never change ...
1
vote
1answer
68 views

Nernst Equation for Lithium ion battery

For electrochemical cells we know $$ \Delta G = \Delta G^{\ominus} + RT\ln Q=- RT\ln Keq + RT\ln Q=-nFE $$ So for lithium ion batteries the reactions are Cathode $$ \ce{CoO2 + Li+ + e- <=> ...
-1
votes
1answer
47 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 ...
0
votes
1answer
67 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 ...
1
vote
1answer
38 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 ...
0
votes
1answer
38 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? ...
1
vote
0answers
32 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 ...
0
votes
0answers
13 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 ...
4
votes
1answer
71 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 $\...
0
votes
1answer
25 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.
1
vote
0answers
27 views

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 ...
0
votes
2answers
46 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 ...

1
2 3 4 5
27