Questions tagged [electrolysis]

For questions about the chemical concepts of electrolysis.

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56 views

Determining the theoretical mass of gas produced through the process of electrolysis

I have a question that has been stumping me for quite some time. I wish to calculate the mass of gas that is produced from varying concentrations of salt (NaCl) through the process of electrolysis. I ...
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2answers
324 views

Lead-Acid Battery: Standard Electrode Potential

I'm making a lead-acid battery for an investigation. Since I only had sulfuric acid and lead electrodes, I decided to firstly run 2 lead electrodes through electrolysis in a sulfuric acid electrolyte. ...
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0answers
32 views

What would affect the rate of recharge of a lead-acid battery?

I am trying to perform an investigation regarding lead-acid batteries and would like to specifically look into the recharging mechanism. However, I realised that this might be quite difficult since ...
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2answers
14k views

Electrolysis of diluted sulfuric acid

My teacher told me that electrolysis of dil. $\ce{H2SO4}$ (concentration below $50\%$) using inert electrodes results in gradual increase of the concentration of $\ce{H2SO4}$. I can't seem to figure ...
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1answer
571 views

Oxidation of aluminum and manufacturing of electrolytic capacitors

My background is in electrical engineering. Recently I saw instructions on how to manufacture electrolytic capacitors at home by mixing sodium bicarbonate (baking soda) to distilled water, submerging ...
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1answer
2k views

Electrolytic refining of copper

In refining copper, an aqueous solution of copper(II) sulphate is electrolyzed, using impure copper as the anode and pure copper as the cathode. At the anode, metal impurities higher than copper in ...
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0answers
100 views

Energy needed for electrolysis of aqueous NaBr [closed]

I'm trying to find the amount of energy it would take to electrolyse sodium bromide to get 1 mole of Br2. I'm not sure how to go about calculating this figure. If anyone could help me out, I'd be very ...
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0answers
135 views

Cation falling off electrode after electrolysis

I'm trying to find the electrochemical equivalent for zinc in an experiment. I am carrying out electrolysis of zinc sulfate solution. According to Faraday's law, m=zq. I made a 0.1 M solution and ...
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2answers
721 views

How to separate two or more gases into different containers

I know this is probably an incredibly stupid question, but I'm making a hydrogen generator for a project. The basis of it is electrolysis of baking soda and water, which apparently gives off hydrogen, ...
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0answers
248 views

Does Reduction Potential affect rate of electrolysis

I am currently doing a project on electrolysis, and I was wondering if the reduction potential (ie. $E^0$) will affect the rate of electrolysis. In other words, across different cells with differing $...
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135 views

Can a nitro compound be reduced to an amine by electrolysis?

Several methods are known for the reduction of a nitro compound to an amine, including catalyctic hydrogenation. I am wondering if this can be done by electrolysis. If we take the simplest ...
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1answer
1k views

Can nitrate and sulfate ions be oxidised during electrolysis of their molten compounds?

$$\begin{align} \ce{O2 + 4H+ + 4e- \;&<=> 2H2O}\quad\quad &&E^\circ = +1.229\ \mathrm{V}\\ \ce{S2O8^2- + 2e- \;&<=> 2SO4^2-}\quad\quad &&E^\circ = +2.01\ \mathrm{V} ...
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2answers
390 views

How connecting galvanic batteries in series actually works. “In Series” detection experiment

How I am interested in understanding what is the actual mechanism behind increasing potential in simple galvanic cell connected in series. Almost all explanations I found on internet are more like ...
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0answers
93 views

Electrolysis of brine with filter paper bridge [duplicate]

What would be the problem with connecting the two dishes up with a piece of metal wire?
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1answer
175 views

Salt Water Metal etching 50 (Euro-)Cent Coin

I want to etch the 50 Cent Euro Coin using this following technique that I came across on some DIY site: Immerse the coin and some disposable piece of metal in salt water such that they do not touch ...
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1answer
7k views

Direction of flow of current in electrolytic cell [duplicate]

In an electrolytic cell, does current flow from Anode to Cathode or Cathode to ...
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0answers
141 views

Problem in anode in experiment of electrolysis of brass

I am studying the electrolytic determination of copper content in brass (~58% copper, ~40% Zn and other trace elements) by using standard method BS EN 16117-1:2011. Now the electrode used for the ...
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0answers
116 views

Why does conductivity of electrolyte solutions peak at high concentrations?

I've recently done a lab about conductivity of brine over time (high concentration salt water). I passed current through salt water and measured the current over time. The graphs I got showed that ...
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1answer
364 views

Black Sludge Appearing When Making Iron Oxide Through Electrolysis

I am trying to make iron-oxide through electroylsis to make thermite. I'm using nails for the iron on the positive electrode in salt water. While there definitely is a good amount of rust collecting, ...
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2answers
45 views

Is my electrolysis emitting compounds from additional reactions?

I am separating water into hydrogen and oxygen via electrolysis. The electrolyte solution is sodium hydroxide (NaOH) in deionized water. Electrodes are 99.96% pure nickel. All gases and liquids are ...
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1answer
597 views

Is it possible to improve electrolysis rate without increasing heat?

I'm separating water into hydrogen and oxygen by connecting a DC current to 99.9% pure nickel electrodes in a solution of NaOH in deionized water. It works great, except that any attempts to increase ...
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1answer
1k views

Voltage needed for electrolysis of water

Reading the wiki for electrolysis it reads that a potential of 1.23V is needed to separate hydrogen from the oxygen. With that being said, how was that calculated? Does it change with the water volume ...
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220 views

Does a zinc metal coating react with coffee in a coffee grinder?

I'm restoring an old coffee grinder and I want to give the grinder mechanism a nice zinc / silver coating. But I read it is not safe for zinc to be in contact with acidic foods. When I look at the ...
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119 views

Thought Experiment: Is it possible to preserve the charge imbalance present during molten lead(II) bromide electrolysis?

Suppose I were to electrolyse some molten lead(II) bromide. According to what I have been taught, the lead ions travel towards the cathode and are reduced at it, while the bromide ions are oxidised at ...
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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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2answers
4k views

Why can higher voltages lead to less efficient electroplating?

I was reading up on electroplating and I came across some things which really confused me: Faraday's First Law says that the amount of metal plated onto the cathode is proportionate to the current, ...
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1answer
1k views

Will KOH work in place of NaOH as the electolyte in the electrolysis of water?

I am making a hydrogen and oxygen generator by electrolysis water. I found out that using salt as an electrolyte creates a compound of chlorine and oxygen with my electrodes clouding up the water and ...
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1answer
1k views

How does electrolytic conduction depends on the size of ions & their solvation?

The textbook says, The smaller the effective size of the ion after solvation, the greater will be its conducting power." But, on the Internet, it is explained as follows: Radius decreases, ...
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1answer
314 views

Electrolysis involving K+ and Li+ ions

Need clarification on Q31a) in the image. Possibly a dumb question but the book's answer might be wrong. The book says lithium ions will be reduced instead of potassium ions. How is this true when K+ ...
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1answer
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How do I determine which is the reduction reaction in a hydrogen peroxide and potassium permanganate solution?

How was it determined that $\ce{MnO4-}$ was reduction, and $\ce{H2O2}$ was oxidation? Also, why wasn’t the equation $$\ce{MnO4- + 2H2O + 3e- -> MnO2 +4OH-}$$ used? Or the $$\ce{H2O2 + 2H+ +2e- -&...
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0answers
135 views

White mucous substance forming around iron paper clip during electrolysis

I'm using a graphite cathode and an iron paper-clip anode, in a saltwater solution, basically to produce rust. I've done this before with no complications, but this time I noticed a white, mucous ...
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232 views

In a hydrogen fuel cell stack, is pure oxygen required?

I have been researching making a hydrogen fuel cell to produce electricity. However, since pure oxygen is expensive, is pure oxygen needed for the dry fuel cell stack or can the oxygen in the air be ...
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1answer
32 views

Chemicals for electrochromic reaction ? [closed]

I would like to detect the electric current going through the water solution using the colour reaction in this water solution. What chemicals can be used for this solution to make it electrochromic.
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Balancing simple Redox equation [closed]

How would you balance these two redox equations? Would you add a '2' in front of Pt2+ and a '2' in front of H+ ?
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298 views

Reason of dissociation of water molecule in electrolysis

$\ce{H2O}$ molecule is dissociated into $\ce{OH-}$ and $\ce{H+}$ ions on reduction at the cathode in electrolysis. But what happens at the atomic level to $\ce{H2O}$ that proton and hydroxide ions get ...
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0answers
369 views

Copper (II) oxide during CuSO4 electrolysis

I was performing copper (II) sulfate electrolysis (graphite electrodes; 10V; 0,01A) today and I observed black precipitate falling from around cathode. I suppose it's copper(II) oxide. I couldn't find ...
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1answer
118 views

When water undergoes electrolysis where in the beaker does the water molecule break apart?

When I was thinking about it I remembered reading two things, one was that certain gases "form" on certain electrodes. The other was something like, such and such ion "travels" towards such and such ...
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1answer
72 views

Can molten Strontium and Barium Hydroxides be electrolysed to give the metals?

Can strontium and barium hydroxides be electrolysed to give the metals? I've noticed they have relatively low melting points. What challenges would this present?
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1answer
8k views

Why is bromine produced at the anode when aqueous sodium bromide undergoes electrolysis?

The electrode potential for Bromine is $\pu{+1.07V}$ whereas for Oxygen to be produced it is $\pu{+0.40V}$. $$\ce{O2 +2H2O + 4e- -> 4OH-}$$ As the electrode potential for bromine is higher, it ...
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105 views

Does electroplating fall off if I disconnect electrolytic cell?

So I understand the basic mechanism of electroplating. I want to ask is there any chance that the electroplating may fall off if I disconnect the electricity supply? As a consequence, should I ...
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703 views

What gases would be produced from the electrolysis of distilled water and sodium bicarbonate? [closed]

I have two questions: one practical question and one conceptual question. 1) I'm trying to set up an electrolysis experiment and I am trying to make sure I am going to end up with the gases that I ...
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1answer
411 views

Why copper wires submerged in salt (or fresh) water oxidize much faster while they conduct electrical current?

On a lot of flooded vehicles (salt/fresh water), I've noticed that wire that carries more current is always the one with most destruction (at the connector/splice), in comparison with lower current ...
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1answer
380 views

Forming hydrogen sulfide from electrolysis of sodium thiosulfate

So I was doing electrolysis on two silver electrodes and sodium thiosulfate. Some observations The voltage drops extremely fast from 2 V to less than 1 V in 15 minutes, possibly because of the ...
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2answers
1k views

What pressure is created by the electrolysis of water?

I am interested to know what is a reasonable maximum working pressure I could expect against the evolution of oxygen and hydrogen when electrolysing a typical water electrolyte. My aim is to make ...
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905 views

Why isn't mercury electrode used to produce commercial element sodium?

I know that while electrolysing a solution of brine, if we use mercury cathode, we get sodium amalgam instead of having hydrogen gas liberated. Even the Castner-Kellner process uses this to produce ...
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1answer
497 views

Heat energy vs. electrical energy in a galvanic cell or in an electrochemical reaction

How can someone determine heat energy released during an electrochemical reaction? Let's assume a simple galvanic cell at standard environment: $$\ce{Zn(s) -> Zn^2+(aq) || Cu^2+(aq) -> Cu(s)}...
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1answer
192 views

Calculating the E of a galvanic cell

So, I have $\ce{Cr2O7^2-(aq) + 14 H+(aq) + 6 I-(aq) -> 2 Cr^3+(aq) + 3 I2(s) + 7 H2O(l)}$ and I know the concentrations to be like so: $\ce{[Cr2O7^2-]}= 1.6\ \mathrm M$ $\ce{[H+]}= 2\ \mathrm M$ ...
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1answer
101 views

Alkaline Water Electrolysis with RbOH

In industry, it appears the alkaline water electrolysis is largely done with solutions of NaOH or KOH - presumably due to low cost. I presume that alkaline water electrolysis is possible under RbOH, ...
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1answer
21k views

Electrolysis of AgNo3 [closed]

I have a solution of $\ce{AgNO_3}$ (is diluted with water). I electrolyse it. What products from at anode and cathode.
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1answer
769 views

Silver Nitrate Electrolysis

i have a solution of silver nitrate at 1M. the aim of my experiment is to determine in 40 mins, how much Ag will be deposited. Should i use copper or graphite electrodes.