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
216 views

what should be the onset potential using cyclic voltammetry?

I am working for PEM fuel cell cathode material. I am confused regarding the onset potential determination for my catalyst (CV attached, fig 1 is complete CV while fig 2 is its zoom image for clear ...
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10 views

Equation for Electrolyte concentration

What is the equation between conductance and concentration of electrolytes in a liquid? I know how to get the conductivity and thus electrolyte level. But was wondering if there is an equation to find ...
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139 views

Kohlrausch Law and conductivity

Im writing up a lab report at the minute and part of it concerns ions in solution and how they affect conductivity. I've been doing lots of reading and I think ive got the grasp of most of it, but its ...
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1answer
2k views

Copper layer doesn't stick after Copper electroplating

I am playing around with copper plating using Copper Sulfate solution with electricity. I am using 2-2.5 volts as power source and around 100-500 mA. It is actually a very small container around 100 ...
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1answer
75 views

Current in a Lithium Ion Battery

I am trying to find the current transferred to the anode and cathode of a Lithium Ion Battery at different voltages. I know the temperature (approximately) of the battery, the battery's starting ...
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18 views

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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50 views

How does solution which electrodes are immersed in effect electrode potential?

There was this question I had to do on which went like "which all metals can we not extract using electrolysis from aq soln" the answer involved the effect of solvent on electrode potentials, can ...
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1answer
28 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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1answer
11k views

If electrolysis splits water, why does only either hydrogen or oxygen (but not both) bubble up on one pole?

If electrolysis splits water, then that means that $\ce{H2O}$ is split into $\ce{H}$ and $\ce{OH}$ or $\ce{O}$. How come that if a water molecule is split at e.g. the negative pole (anode), only the ...
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34 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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6k views

Electrolysis of concentrated sulphuric acid

In my textbook it is given that for electrolysis of dilute sulfuric acid at anode following reactions can occur: At moderate concentrations $\ce{2H2O -> O2 + H+ +4 e-}$ And for high ...
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2answers
4k views

Why do positive ions go to the cathode?

In electrolysis why do positive ions go to the cathode? Since the cathode is positive, won't the positive ions face repulsion at the cathode and would require more energy? I understand that reduction ...
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1answer
36 views

Can I anodize an aluminum coating on steel to have better corrosion inhibition for the steel?

I am planning to coat aluminum on steel and I want to give the steel its maximum corrosion protection. Is anodizing the coating necessary?
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1answer
62 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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4k views

What is the role of hydrochloric acid in a copper electroplating bath?

Considering water as a given, the third most important ingredient in a copper electroplating solution, as a short survey of related recipe webpages will show you, is hydrochloric acid (HCl). Here's a ...
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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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3answers
5k views

Is it dangerous to inhale the steam coming from electrolysis of salt-water solution [closed]

Is chlorine in there that accumulates (at the anode) and emerge out as chlorine gas? I was worried since I added a pinch of salt to the steamer in order to hasten the heating of tap water when I ...
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1answer
5k views

How to identify the anode and cathode in a concentration cell?

How do I understand which is the anode and which is the cathode in this problem? We have a concentration cell with hydrogen electrodes. It's made up of two half-cells. One half cell contains [BaCl(...
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55 views

Does the salt bridge in a galvanic cell deplete over time?

I searched for the answer for this question on Wikipedia and Stackexchange a lot but couldn't find same question or a required answer in some other similar question. I understand that the function ...
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1answer
44 views

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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1answer
4k views

Does the concentration affect the voltage in electrochemistry?

For my electrochemistry lab I'm using $\pu{10 mL}$ of $\ce{ZnSO4}$ and $\pu{10 mL}$ of $\ce{CuSO4}$ solutions connected with a salt bridge. I connect $\ce{Zn}$ metal and $\ce{Cu}$ metal to a voltmeter ...
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23 views

Are there any chemical pathway or catalyst that could produce electricity from fossil fuel without combustion?

While oil and fossil fuel are dense in energy. I have known only one way to retrieve energy from it, which is burn it. I wish it should have some way we could have a way to get energy from it without ...
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39 views

Calculate voltage, cost and time of nickel coating

To nickel with a bath of $\ce{NiSO4}$ a cathodic current of $\pu{0.3 A/cm2}$ is applied with a square plate of side $\pu{5 cm}$ is used to nickel a certain substrate. Due to the formation of $\ce{H2}$ ...
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24 views

Copper plating with switched anode and cathode [closed]

Please help! I was working on a mock research project/lab for my chemistry class testing the rate of electroplating of copper vs. voltage. I had copper and nickel electrodes and .1M copper sulfate ...
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2answers
209 views

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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3answers
5k views

How to calculate the solubility product for PbS from galvanic potential?

Knowing that at 25 °C the following galvanic cell: $$\ce{Pb~|~Pb(NO_3)_2~1M~||~PbS~saturated~|~Pb}$$ shows an $\mathrm{EMF} =0.413~\mathrm{V}$, find the $K_\mathrm{sp}$ of $\ce{PbS}$. My Approach ...
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1answer
34 views

Why is the cathode of a lithium-ion battery metallic, which is the opposite of most other batteries? [closed]

In most types of batteries, primary and secondary, the metallic electrode is the anode, and a non-metal acts as cathode. Or a pure metal is the anode, and the cathode is a metal oxide. Why is the ...
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27 views

The physical intuition behind some simplifications in electrochemistry

Find the standard reduction potential of $$\ce{AgIO3(s) + e- <=> Ag(s) + IO3-}.$$ $K_\mathrm{sp} = \pu{3.1E-8},$ and the standard reduction potential of $\ce{Ag +e- <=> Ag(s)}$ ...
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1answer
27 views

Is it possible to calculate the 'overall' redox potential of a system?

For a solution where many redox reactions occur (e.g. cytosol, soil solution), can we consider anything as 'overall' redox potential of a system? Is there a formula to quantify it in relation to the ...
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7k views

Why does increasing number of salt bridges increase voltage of electrochemical battery?

In an experiment, I set up a cell with lead nitrate (w/ lead electrode) and zinc sulfate (w/ zinc electrode), with a salt bridge containing potassium nitrate. I observed that by increasing the number ...
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3answers
97 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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1answer
36 views

Standard Reduction Potentials and Electropositivity

I was looking through a table of standard reduction potentials and the trend seemed like it correlated with electropositivity. Is it reasonable to qualitatively compare two metals to see which has a ...
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1answer
75 views

What is the electrochemical reaction of this battery?

I've watched a YouTube video "Soda Can Battery - Power From Trash - DIY Project" by Source Port Services. I understand that the anode can be oxidised, but what is the reduction reaction at the cathode?...
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25 views

Can salvaged Nickel Metal Hydride from NiMH batteries be used in Nickel Plating?

In my understanding of nickel electroplating, nickel is used as the anode and it is also dissolved in an electrolyte to form nickel ions, which eventuallly deposits onto the cathode. I don't know the ...
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2answers
40 views

Equilibrium of an electrochemical cell [closed]

I am quite new to the field. So try to figure out what is meant by the equilibrium state of an electrochemical cell? Is it, where both half cells passing the same number of electrons to either side? ...
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1answer
35 views

Electrolysis of calcium hydroxide in glycerol [closed]

Calcium hydroxide is soluble in glycerol. Assuming anhydrous conditions, could such a solution be electrolysed to yield calcium metal, or would glycerol OH groups interefere with the process?
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1answer
42 views

Feasibility of using ionic liquid fuels in an MHD type reactor

First off I would like to say that my knowledge on chemistry, even general chemistry, is basic if not poor. That said, I have some intuituions on this matter. I haven´t found any paper regarding ...
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1answer
27 views

Electrolytes in electrochemical half cells

In most of the examples in my book I have come across, the electrolyte for an electrochemical half cell has always been the aqueous version of the metal used. For example, a silver electrode is ...
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1answer
101 views

Why would water, and not saltwater, undergo electrolysis?

I am attending a cram school and there was a question that goes: Electrolysis decomposes chemicals by passing an electric current through a liquid or solution containing ions. Which of the ...
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2answers
12k views

Derivation of relationship between Gibbs free energy and electrochemical cell potential

Why is $\Delta G=-nFE?$ I don't understand what the motivation is behind this definition. Was it derived or just given? The textbook provides no justification for this equation. In fact, much of the ...
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1answer
46 views

Energy required for obtaining required mass of aluminium from alumina via electrolysis

How do I know how much energy I need to obtain 20 g alumunium from alumina with 5 V? I calculated the quantity of electricity is 2.22 F. Any help appreciated!
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1answer
34 views

Ponderomotive Effect on Ionic Liquids

Would an alternating electric field cause net motion of ions in a liquid in the case of the electrodes being placed outside the liquid? Generally speaking, what happens if you apply an external ...
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1answer
44 views

How to know which reduction and oxidation reactions occurred?

We just had a lab experiment on galvanic cells and we used 0.5 M and 1 M iron(III) nitrate solution at the anode (iron electrode) and 1 M and 0.5 M copper(II) nitrate solution at the cathode (copper ...
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1answer
88 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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2answers
80 views

Troubleshooting electrochemical batteries

For my science classes, I have built multiple types of electrochemical batteries utilizing oxidation-reduction reactions, and I have demonstrated that they each produce potential difference across the ...
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2answers
129 views

What determines the speed of charging of a battery?

I was told on physics.stackexchange that this question belongs to Chemistry, what do you think? Recently we have seen the surge of superfast mobile phone charging. Just an example: http://www.bbc.com/...
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38 views

Reduction potential as a function of pH

I have read that Latimer diagrams can be represented both in an acidic medium (pH = 0) and in a basic medium (pH = 14). I would like to know how to calculate the reduction potentials as a function of ...
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1answer
60 views

What is the interaction between dissolved ions of opposite valence in a solution at rest?

NaCl is dissolved in water. Ions sodium and chloride are sufficiently free from each other so that they may occupy different regions of the solution after an active transport process through a ...
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0answers
37 views

Help understanding Electrochemistry diagram

I was reading some literature when i came across the following figure and was wondering if someone could help explain it to me. I see on the vertical axis it is potential vs Li/Li+ and see that Oxides ...
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1answer
437 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 ...