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Questions tagged [electricity]

For questions involving electricity in the scope of chemistry. Note that questions about electrical circuits, semi-conductor diodes, etc. are off topic and more suited for EE.SE or Phy.SE.

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Is it possible to generate electricity by using two inert electrodes in a galvanic cell?

The Daniell cell has two active electrodes, meaning that both the copper and the zink electrodes participate in the redox reaction. However, in a lemon battery for example, the copper electrode is ...
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1answer
27 views

Atoms in Solar Cells

An electric field in solar cells is created through photons knocking electrons off of atoms. What happens to the positively charged atoms once the electrons have been knocked off? Furthermore, are the ...
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0answers
31 views

Question about the composition of a 1902 non-polarisable electrode diagram by Jagadis Bose

In his work, "Response in The Living and Non-living" (1902); page 6, Jagadis Bose describes a method for detecting nerve response. He explains that he uses iso-electric contacts with no current in the ...
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1answer
280 views

In the simplest terms, what is exchange current density?

what is exchange current density, and ideally how does it relate to overpotential I know it's related to the amount of dynamics in a reaction, so it can tell us how simple or complex a reaction ...
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0answers
47 views

Why do electrons not flow through the electrolyte? [duplicate]

Why do the electrons not flow through the electrolyte instead of the external circuit in a electrolytic cell connected to an external circuit? I mean, if an electrolyte is a conductor why would the ...
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1answer
133 views

What is the definition of current efficiency?

What is the exact definition of current efficiency of an electrolytic cell? I've looked online and there is no suitable answer to it. I thought current efficiency would be the amount of electrons ...
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1answer
920 views

Why is AC current used rather than DC current for calculating the conductance of a solution(see body)? [closed]

I was reading the answer of the above question from a book. it said that while using DC current, electrolysis occurs. Hence it affects the conductance of the solution. But if any gaseous product is ...
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0answers
37 views

Is it possible to have a fully opaque 'switch glass'?

Current switch glass (smart glass) technology permits for a transparent glass to become semi-transparent, i.e., translucent. For my application, I was wondering if it was possible to make a 'smart ...
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1answer
31 views

Why the DMM (multimeter) register negative resistance when measure a drop of hydrochloric acid [closed]

I noticed that when I put the multimeter electrodes (in the ohmmeter mode) in a drop of hydrochloric acid with mild concentration (15%) the multimeter displays negative values. Can someone explain ...
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1answer
1k views

Do plasma globes generate ozone?

My kids and I were playing with a small plasma globe like this: After touching it we all noted a faint smell like that created by other high voltage static discharges, which I always understood to be ...
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1answer
84 views

If two atoms “fight over” one electron, who will win? [closed]

If two atoms of different elements are both missing exactly one electron in their valence shell so that they have a charge of +1 and we place an electron between them, exactly in the middle. Which ...
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0answers
242 views

Magnetic work and the first law of thermodynamics

We commonly encounter the first law of thermodynamics in the form $\mathrm{d}E = T\mathrm{d}S - p\mathrm{d}V + \mu\mathrm{d}N$, which notes the contribution of thermal, pressure-volume, and chemical ...
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1answer
61 views

Do electrons truly flow in circuit? [closed]

I know this sounds like a stupid question, but do electrons truly flow in a circuit? It doesn't seem logical for electrons to just break away from their atoms to go move through a circuit. If they did,...
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5answers
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Does chemistry change under high voltage?

Do chemical reactions change when you charge the entire reaction vessel plus or minus $\pu{1 MV}$ or more? Is there a name for such chemistry? I was looking at "electrochemistry" expecting to see a ...
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0answers
44 views

Chemistry of charging an insulator material

Earlier this year, I had learnt in Physics class that rubbing two different materials against each other can charge the materials (i.e. cause each material to either be positively-charged or ...
9
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1answer
401 views

What is the underlying chemistry behind the triboelectric effect?

I remember briefly studying the triboelectric effect in Physics but as I now approach the domain of Chemistry, I'd like to know what processes are involved (at the molecular level) when the the ...
4
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1answer
83 views

What is the effect of Helium-based surroundings (99% Helium) on electrochemical gas sensors?

I am currently working on a project measuring gas composition of car exhaust. In order to dilute the gas concentration down to something electrochemical sensors can read, I diluted the sample with ...
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1answer
1k views

How does a salt bridge in a galvanic cell neutralize each half cell? [closed]

I am not exactly sure what purpose the salt bridge has. In the above image, I understand that electrons flow from $\ce{Zn}$ through the wire to $\ce{Cu}$ due to the redox reaction. However, I do not ...
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2answers
4k views

How exactly are ions in a Mass Spectrometer accelerated?

After a molecule is ionised, the ion is accelerated by an electric plate up to a certain kinetic energy by the attraction of the ion to the electric plate. However, after the ion has passed the ...
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2answers
230 views

Why won't removing the salt bridge cause the battery to recharge?

If I understand correctly, the salt bridge in a battery is used to move positive ions towards the side that is becoming more negative, and negative ions towards the side that's becoming positively ...
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1answer
255 views

Electrochemical series - when not at standard conditions

Is there a reason why this question's answer is treating it as if it is at standard conditions? Isn't it using 0.2M aqueous solutions, so the electrochemical series won't be valid for this question? ...
5
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2answers
77 views

What are the ideal pair of (everyday) elements to pair in a thermocouple

I want to create a thermocouple (to carry out experiments on thermoelectricity). I want to use the pair of everyday* elements (e.g $\ce{CuO}$ and $\ce{Al}$ wires) to create the thermocouple. The ...
3
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1answer
260 views

Why don't all electrodes produce the same results in the electrolysis of potassium iodide?

While in lab, I accidentally used two paper clips while trying to electrolyze potassium iodide and all I saw was was phenolphthalein turning pink at the cathode and no brown at the anode. I asked my ...
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1answer
80 views

Will electric field make organic matters (e.g. glucose) ionize in water?

After reviewing this post, I have a new question regarding ionization and dissolution. If applying a strong electric field (DC or AC) in a water solution, will the electric field ionize the organic ...
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2answers
2k views

Could a lead-acid battery electrolyte be replaced by hydrochloric or nitric acid?

Hydrochloric acid, as well as nitric acid, are also strong acids like sulfuric acid. So, why are not they used commercially in lead-acid batteries?
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2answers
115 views

Ni-Mh battery makes fizzy sounds while and after charging - why and do I need t replace it?

I have some Ni-Mh rechargeable batteries (size AA/Mignon 1.2V, 2100 mAh) and just started to charge them using an automatic charger with 450 mA output. Now one of those batteries surprisingly started ...
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0answers
66 views

Electrically non-conductive molten salts

I'm researching an idea for molten salt as a coolant. The information that I lack is the conductivity of molten salts. Specifically, I would like to know of electrically non-conductive (or, at ...
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0answers
338 views

Why does my voltaic pile produce a higher voltage then predicted?

In my chemistry class we are building our own voltaic cells and trying to produce as much current as possible with materials we are given using redox chemistry. My lab partner made a battery without ...
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0answers
452 views

Is polymeric ethylene glycol conductive?

The other day, when we were doing the chapter Polymer Chemistry my teacher mentioned that Polymeric Ethylene Glycol (PEG) is conductive. [EDIT- By 'conductive', I guess my teacher meant, "...
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1answer
35 views

Way to express charges? [closed]

I would like to ask a question regarding electric charge. I see that charge has $2$ units. Elementary charge Coulomb For example A proton has a charge of $+1e$ or of $+1.602 * 10^{-19}$ Coulombs. ...
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1answer
126 views

Is Lightning Basically a Cathode Ray?

I've heard the term cathode ray pretty much every year in school since they introduced chemistry, and I know that it's a stream(?) of electrons. I'm just having troubles relating it to the real world. ...
4
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1answer
919 views

Why do gases under low pressure conduct electricity?

In J. J. Thomson's cathode ray experiment, he used a discharge tube in order to make the gas inside conduct electricity. Why do gases under low pressure conduct electricity?
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1answer
127 views

Change of potential difference during electrolysis while adding salt

I was conducting a simple experiment at home on electrolysis. Obviously, when you build a circuit with a 9V battery, a lamp, and put two electrodes in water you measure a potential difference of ~9V ...
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1answer
547 views

On Electrochemical Cells and Salt Bridges

We're studying the topic Electrochemistry at school now, and I've got a few doubts regarding electrochemical cells and salt bridges. What I am going to do is listing out (point-wise) what I ...
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1answer
972 views

Why do electrolytic concentrations affect voltage in electrochemical cells?

I know that the voltage of a cell is calculated via the Nernst Equation as $$E_\text{cell}=E^\circ-\frac{RT}{nF}\ln Q_\mathrm r$$ where $Q_\mathrm r$ represents $\frac{\text{concentration at the anode}...
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0answers
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Why do we have surface charges on a polymer sheet immerged in water ?

I am working with a conductive polymer sheet where I have dropped off a drop of water (with ions). I have plugged the polymer with a conductive wire and an other wire is on the drop. With a voltmeter ...
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0answers
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How does SOFC work?

The Solid Oxide Fuel Cell is a particular case in which an oxide is used as a conductor. Once i've heard that oxides usually aren't good conductors but it turned out that a lot of oxides are ...
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0answers
203 views

Why is kerosene destroying just my red LEDs?

Due to the nature of the problem, I've decided to post this on chemistry.stackexchange and not electronics.stackexchange, since I believe that the problem is chemical in nature. Long story short - we ...
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2answers
426 views

Placing oxygen molecule into electric field

I am trying to understand what happens inside various types of air ionisers. Some of them are sold for their purported health effects (which I do not want to discuss here), another type are used in ...
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2answers
281 views

Building a Voltaic Cell Without Metal Ions

For an assignment in my Chemistry class we have to build a voltaic cell using materials that are provided to us and that outputs a voltage as close to 0.8v as possible. The list of materials is as ...
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1answer
132 views

Compound with a bright green emission when electrically excited

I rolled back the edit because I really am looking for the following: I am looking for an element or compound that would have a bright green emission when electrically excited and is a gas at between ...
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1answer
84 views

How can a conductivity experiment have higher voltage than battery?

I did an experiment where I tested the conductivity of different solutions and some substances. We connected a 9 bolt battery, some aluminum foil sticks, and a multimeter that reads the voltage. It ...
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1answer
499 views

Formation of Bands in Semi-Conductors

At school, we are learning about semi-conductors and their applications in modern electronics. One of the features of semi-conductors is that there is a small energy gap between the valence and ...
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1answer
627 views

Entropy Change of Resistor

A very large swimming pool filled with water of temperature equal to $20\ \mathrm{^\circ C}$ is heated by a resistor with a heating power of $500\ \mathrm{W}$ for $20$ minutes. Assuming the water in ...
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1answer
879 views

In a galvanic cell where the two electrodes are in the same electrolyte solution, why do reduction and oxidation occur separately?

In a certain book, I was presented with the following solution: An iron nail is attached by a piece of wire to a magnesium ribbon, and the iron and magnesium are placed into the same container, with ...
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1answer
106 views

Charge, Size, and Movement in Aqeuous Ions as Electrolytes

Would a pair of aqueous $+2$ and $-2$ ions necessarily conduct electricity better than the same concentration of $+1$ and $-1$ ions? Furthermore, would more massive ions not conduct as well as less ...
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0answers
245 views

Hydrogen Peroxide - Iron Nail Galvanic Cell?

I am planning to create a simple galvanic cell made up of common household materials. Suppose I have hydrogen peroxide (to serve as cathode), diluted in water, in one beaker, and I have a bunch of ...
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1answer
491 views

Why did my lemon and penny battery fail?

I followed instructions in Popular Mechanics publication for making a battery using lemons and pennies but it didn't work. I have a few ideas on why it might not have worked and would like to know ...
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2answers
1k views

Electrolysis of Water: Overvoltage?

I've heard from a few sources that over-voltage in a electrolysis cell for water will cause a greater heat buildup with no yield. Is this true, and if it is, why is it true? From my electronics ...
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1answer
70 views

Placement of Electrodes for Electrochemistry?

I'm kind of curious as to the relationship between resistance and the yield of electrochemical methods. If I have my electrodes rather close together in a conductive solution the resistance will be ...