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Questions tagged [electrolysis]

For questions about the chemical concepts of electrolysis.

Means to cut ("-lysis") with electricity ("electro"). Electrolysis is the use of a direct electrical current to drive an otherwise non-spontaneous reaction. Electrolysis is often used to extract reactive elements from their ores. It can also be used to split water into hydrogen and oxygen gas.

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Tin(II) chloride electrolysis problems: (1) Why is the tin dendritic? (2) Why does the unconnected metal in the middle also act like an electrode?

I'm watching this tin(II) chloride electrolysis video: https://www.youtube.com/watch?v=coPGazAaVBE&ab_channel=FlinnScientific Two phenomenon puzzled me, and I couldn't find a good explanation on google- (1) Why is the tin metal dendritic when it's…
Wang
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How does voltage and resistance affect an electrolysis?

At school we've learned about calculating the voltage needed to perform an electrolysis. The current is how many electrons pass per time. The formula is given $$I = \frac UR$$ This means that given an electrolysis with $U=\pu{4.0 V}$ we get $$I =…
Friend of Kim
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How much CO2 is created during water electrolysis with a graphite anode?

I'm experimenting with water electrolysis and wanted to use non-toxic materials, so I settled on pure graphite rods for both electrodes and Epsom salt (magnesium sulfate) as the electrolyte. The system works reasonably well, but upon further…
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Why does electrolysis of aqueous concentrated sodium bromide produce bromine at the anode?

It is often stated that electrolysis of any aqueous concentrated halogen compound will produce the halogen at the anode, despite it having a more postitive standard electrode potential than the oxidation of hydroxide, while when it is dilute oxygen…
ASP
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Why does adding an acid speed up electrolysis of water?

I've read in several places that when electrolyzing water into $\ce{O2}$ and $\ce{H2}$, that adding a salt or an acid will speed up the process. Why is this?
Friend of Kim
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Is it safe to inhale O2 from electrolysis of a pH 13.7 KOH solution?

I'm conducting electrolysis of water with a 0.25M KOH solution in water (about 14 on my pH meter) using graphite electrodes, and I was wondering if the O2 would be safe to inhale, as in an oxygen bar?
wordsforthewise
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What is going on in this reaction?

I was trying to remove the electroplating from a aluminum rod using inverse electrolysis and everything went wrong. I'm definitely not a chemistry expert, so I'd like to know what happened here. I used hydrochloric acid (30%) as the electrolyte, the…
emi
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Autocatalysis / Electroless plating of mercury

As a project I am trying to plate mercury onto a powdered metal amalgam of $\ce{Cu}$ & $\ce{Ag}$. I am using solution of $\ce{HgCl2}$ in normal $\ce{HCl}$ (a reducing agent), Any thoughts for increasing the efficiency of plating process on the metal…
Muzammil
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What's happening to carbon electrodes?

Carbon electrodes are very popular, because unlike metal electrodes, carbon is quite inert during electrolysis (I'm sure that has some explanation based on electronegativity). However they too are not eternally lasting. Especially the pencil…
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Can every conductor be electroplated using copper and sulphuric acid?

I really like electrolysis. Today I bought 30% sulphuric acid to electroplate something with pieces of copper. I've poured half water and half acid in a glass. I connected some cuprextit-copper plate to the anode and outdated aluminium coin to the…
Tomáš Zato
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Production of hexavalent chromium during electrolysis using a stainless steel as the cathode

I want to do rust removal by electrolysis (sodium carbonate, water solution) Can I use a stainless steel basket as a cathode or will it produce hexavalent chromium ? I know if I use stainless steel as the anode it does produce hexavalent chromium,…
Kristian Lerche
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Why is twice as much hydrogen produced than chlorine in the electrolysis of brine?

I have seen a great many number of diagrams which show the electrolysis of brine in a diaphragm cell, but show twice the volume of hydrogen produced. For example: On the other hand, other diagrams show that the same volume of hydrogen and chlorine…
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Using sodium metasilicate as a non-reactive reusable electrolyte in water electrolysis

I'm trying to increase the transport of electricity in the tap water I use in my dry cell electrolyser. Table salt is out, as it rusts the stainless steel electrodes and produces toxic gasses. Lye is caustic to skin and mucous membranes but the next…
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Whats the effect of pressure on water electrolysis of sea water with increase in depth?

I’m currently working on an underwater robot and was hoping to use the gas bubbles produced by water electrolysis for buoyancy control. The operating depths range from 200–1000 m.
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Electrolysis for rust removal: is "line of sight" a showstopper?

So I am using electrolysis to remove rust from a fuel tank. The tank is the cathode and a sacrificial anode is inserted where the fuel pump normally goes. It's not practical to put it anywhere else. However, the fuel tank has internal baffles,…
Harper - Reinstate Monica
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