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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Why conductivity of electrolyte decreases on dilution, but molar conductivity increases?

I learnt that on dilution of an electrolytic solution, it's conductivity decreases. However, there is an increase in the molar conductivity of the solution. The book explained the reason by comparing ...
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44 views

Determine if the following change is an oxidation, a reduction, or neither

The following reaction is not a complete reaction. Determine if the change is an oxidation, a reduction, or neither: $$\ce{CrO4^{-2} -> Cr2O7^{-2}}$$ I know that the answer to this ...
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25 views

How to use salt spray data in real environments?

I want to convert resultant hours of salt spray corrosion test to estimated values in years for real life environments such as marine. In other words, How could I predict the result of real life tests ...
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43 views

Why does temperature affect cell potential?

The Nernst equation describes the relationship between cell potential and temperature. But why does temperature affect cell potential? My understanding is that the collision model of kinetics is not ...
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1answer
26 views

Is the Nernst equation related to ohmic drop?

Let's consider Nernst equation $$E= E^\circ -\frac{2.303\mathcal{R}T}{n\mathcal{F}} \log Q$$ which, once at $298,15~\mathrm{K}$, is the equivalent of $$E= E^\circ - \frac{0.059}{n} \log Q .$$ Does ...
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49 views

How can Nernst equation apply in this redox reaction?

$$\ce{CuSO4 + Zn \rightarrow ZnSO4 +Cu}$$ what is the cell potential of the voltaic cell with copper and zinc electrodes if the system is at 50 degrees and the solutions are both at 1 mol? How can it ...
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41 views

Hydrogen fuel cell - why do the H+ ions move through the electrolyte

Consider the following hydrogen fuel cell http://butane.chem.uiuc.edu/pshapley/Enlist/Labs/FuelCellLab/FuelCell.html At the anode, hydrogen is oxidised (losing electrons). My first question is ...
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11 views

How is streaming potential measured?

This paper describes the measurement of streaming potential using a potential divider configuration. However it is unclear where the potential difference is created. From the diagram it appears that ...
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1answer
14 views

An electric potential is generated when a liquid moves with respect to a solid (streaming potential). Is the reverse true?

Streaming potential is an electrochemical phenomenon that a that relates electric currents with the relative movement of solid and liquid phases in contact with each other. So when a liquid moves ...
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28 views

What happens when you react pure metals with solutions of salts? [closed]

Copper reacts with silver nitrate solution. It produces silver and a blue solid called copper nitrate, $\ce{Cu(NO3)2}$. On a piece of copper there's a coating of solid silver. ...
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1answer
28 views

How to convert sodium aluminate back to sodium hydroxide?

I had dissolved a bunch of aluminium foil in an aqeous solution of sodium hydroxide. The resulting solution consists mainly of sodium aluminate with very little excess sodium hydroxide. What I want to ...
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1answer
30 views

Why is chloridric acid used in salt bridges?

I've been planning an experiment on how to make galvanic cells and during my research I came across an article in which chloridric acid was used, along with a soluble salt and agar-agar, in salt ...
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29 views

Entropy - Negligible?

In electrochemistry, the Nernst equation tells us the cell potential for non-standard conditions. I read that the factor $\frac{-RT}{nF}\ln{Q}$ accounts for difference in cell potential due to ...
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1answer
31 views

Why don't ions have one equilibrium potential? (Nernst equation)

I know that equilibrium potentials are dependent on the ratio of ion concentrations inside and outside of the cell and temperature. I also know that the equilibrium potential is reached when there is ...
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1answer
38 views

How does Zinc become oxidized when it's not in direct contact with Copper ions in a Galvanic cell?

Whenever Galvanic Cell is explained in textbooks/videos it usually starts by showing that if you put a piece of $\ce{Zn}$ in a $\ce{Cu^{2+}}$ ion solution the $\ce{Zn}$ will become oxidized and ...
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1answer
40 views

Why does the potential difference of a current drop, when silver nitrate is added to deionised water?

Semi-related to Why do some salt ions in solution conduct electricity better than others? After conducting more experiments, using deionised water as an analyte only, I found the potential difference ...
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47 views

Concentration of hydrochloric acid for electrolysis?

How much hydrochloric acid (maximum) should I use to do electrolysis of water, and how much amount of voltage should I use to get the maximum of hydrogen and oxygen?
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1answer
32 views

The anode and cathode when corrosion happens

Let's say $\ce{Fe}$ reacts with $\ce{Cu^{2+}}$ ions. $\ce{Fe}$ would oxidize and therefore give electrons to $\ce{Cu^{2+}}$so that: $$\ce{Fe-> Fe^{2+} +2e-}$$ $$\ce{Cu^{2+} +2e^- ->Cu}$$ The ...
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1answer
32 views

Does the speed of an ion affect the current that can flow through a solution?

Typically, when a cathode and anode are inserted into a solution that allows current to flow, the ions are moving with a certain kinetic energy. If the ions were to gain kinetic energy (through ...
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1answer
69 views

Why are potentials of cells with magnesium electrode always lower than expected?

I have prepared the 1M water solution of magnesium acetate. Then I placed $\ce{Mg}$ and $\ce{Cu}$ electrodes in it. I predict there such reactions take place: $$\ce{Mg-2e^- \rightarrow Mg^{2+}}$$ ...
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1answer
110 views

Why do some salt ions in solution conduct electricity better than others?

My experiment involves a potentiometric titration, and I have used $\ce{AgNO3}$ as a titrant and KCl/KI/deionised water only as an analyte. In the image below of my data, the potential difference as ...
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3answers
142 views

Does increasing concentration of copper sulphate decrease or increase its conductivity?

I am a high school student and for my chemistry lab, I did an electrolyis experiment on how the changing concentration of electrolyte (copper sulphate) will change the rate at which the copper is ...
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19 views

Preparing CdSe electrodeposition bath

What is the best way of preparing an aqueous solution containing 5 mM $\ce{CdSO4}$, 1 mM $\ce{SeO2}$, 0.5 M $\ce{Na2SO4}$ and adjusting pH to 3 by adding 0.5 M $\ce{H2SO4}$? What is the ...
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1answer
35 views

Cathodic protection of tubes in Shell & Tube Heat Exchanger

Our $\ce{Cl2}$ liquifier is of the following type: It is entirely made of mild steel (shell as well as tubes plus the connecting pipelines). At shell side there is Freon (R-12) with its ...
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30 views

offset in measuring decomposition potentials

as far as I've understood to measure the decomposition potential of an electrolyte using a galvanic cell we just put two electrodes, connect them to a battery, and vary the external potential till ...
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36 views

Ion-selective electrodes

Some ion-selective electrodes can be expensive (starting from $500). Is there any relatively inexpensive do-it-yourself alternatives that would still give very accurate results? How does one make an ...
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1answer
19 views

Electrode for methanol

Could you advice an electrode for electrophoretic deposition in methanol which won't spoil methanol and also wont be spoiled by methanol. I googled a bit and found that 1 copper, platinum and gold are ...
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1answer
978 views

Why would 1kW power supplies fail around Nitric acid (HNO3) gas?

I experienced a situation where some electrical power supplies (rated over 1kW) were exposed to nitric acid ($\mathrm{HNO_3}$) fumes at roughly 9ppm for half a day; these power supplies intermittently ...
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1answer
96 views

Principle of potentiometric titration

In potentiometric titration between Ascorbic acid and Iodine when we plot the graph between EMF with volume of iodine consumed, we get a sudden decrease in emf at equivalance point,Why? It is also ...
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51 views

Iodometric titration of copper - standard electrode potentials

Upon inspection of the standard electrode potentials for the half reactions for both $\ce{Cu^2+}$/$\ce{Cu+}$ and $\ce{I2}$/$\ce{2I-}$, it becomes apparent it should be the iodide ions that act as the ...
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1answer
40 views

Sacrificial Anodes and Pit Corrosion

I have a slab of aluminum and one part of the slab will be exposed to a very corrosive environment. If I put a sacrificial anode elsewhere on the slab will the section that is exposed still be ...
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1answer
37 views

Is there an isotope effect for diffusion of an ion through a crystal lattice?

Consider the diffusion of natural abundance $\ce{Li^{+}}$ and $\ce{{}^{6}Li^{+}}$ through a crystalline matrix, say a spinel such as $\ce{LiMn2O4}$. The two lithium ions will have the same ionic ...
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1answer
31 views

Unusual color from leaking battery. What happened?

I was removing old batteries from a camera the other day. One of the batteries had leaked something very bright blue. I have seen batteries leak before and typically the colors look a bit like a ...
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1answer
35 views

Can we make a rusting battery

Since in rusting (oxidation) of Iron, transfer of 4 electrons takes place is it possible to use this reaction under catalytic conditions to create a simple electric cell, even if it just gave a ...
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2answers
75 views

Heat given off from an electrochemical cell compared to mixing reactants

My confusion regarding the difference between the heat given off in a reaction that takes place in an electrochemical cell compared to in a beaker/appropriate container when the reactants are simple ...
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2answers
56 views

Reviving a 6 Volt lead-sulfuric acid battery

I have a 6 Volt sulfuric acid battery used to power a golf cart that has all the acid drained out, and the usual solution was to add more water to the battery however I am afraid that would not work ...
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74 views

Cell overpotential diagrams

Is there anyone who knows a book where I can find a detailed explanation of cell overpotential diagrams, like the ones shown here? Thanks in advance!
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75 views

in the electrolysis of H2SO4 solution, when the concentration is increased why does the current increase even when OH- ions reduce?

During the electrolysis of $\ce {H2SO4}$, $\ce {OH-}$ ions are more reactive than $\ce {SO4^{2-} }$ ions and so they dissociate. as $\ce {OH-}$ ions dissociate, they are the negative ions that carry ...
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1answer
60 views

How to accurately calculate the electromotive force for various conditions in a salt water battery?

This question is on the same topic as this one but more complex. So, let's consider the cell with $\ce{Zn}$ and $\ce{Cu}$ electrodes inside the $\ce{NaCl}$ solution. On the $\ce{Zn}$ electrode we ...
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1answer
73 views

What causes electrons to move from zinc to copper?

Here is something that no video in youtube about electrochemistry can explain me about galvanic cells. Suppose we have $\ce{Zn}$ metal immerse in $\ce{Zn^{2+}}$ in one side, then $\ce{Cu}$ metal ...
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52 views

What is the unit of molar conductivity?

Could you explain what is unit of molar conductivity along with derivation
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39 views

What reactions can take place for the reactants $\ce{Ag/Ca^2+}$ and $\ce{Mg/Cu^2+}$?

Explain the following experiments and their results. What is their chemical equations as well? When immersing a Magnesium (Mg) chunk inside aqueous solution of Copper ions (Cu(ii)), a red-brown ...
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1answer
56 views

Why is an electropositive metal like Zinc capable of plating out?

I know that electronegative metals like copper or silver can electroplate out of an aqueous solution in electrolysis. However, I've also noticed $\ce{ZnSO4_(aq)}$ can electroplate out when ...
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1answer
53 views

Why the second ionization energy of helium is greater than the first? [closed]

maybe because the first electron has a lower energy. Why does this happen?
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25 views

Voltage across friend's lemon battery is opposite of expectation?

I'm an EE, and a friend was asking about the direction of electron flow from batteries. I explained about conventional current being the flow of positive charge carriers and told him that electrons ...
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1answer
112 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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1answer
56 views

How to explain the increase in current with the increase in the concentration of responsible ions?

I have conducted an experiment wherein I have used different concentrations of $\ce{H2SO4}$, $\ce{HNO3}$ and $\ce{H3PO4}$ as the electrolytes. I filled the acid in glass tube and used a 9V battery, ...
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23 views

Current In A Circuit [duplicate]

When a battery, by performing work on a charge, moves it to the higher potential, why doesn't the charge move through the battery and return to the low potential, why does it go through the circuit?
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23 views

Galvanic Cells, theoritical voltage [closed]

This reaction proceeds in the galvanic cell: $$\ce{Zn + Pb^{2+} -> Zn^{2+} + Pb}$$ I need the equation for the half-reactions of this cell and the theoretical voltage produced by this cell if ...
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15 views

Debye Length and Ethanolic Solution

What is the Debye length of a conducting metal oxide particle immersed in a $28.7\text{mM}$ ethanolic solution of $\text{CaSO}_{4}$ at $47^{\circ}C$? Assume a dielectric constant of the medium of ...