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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What's the point of hydrogen ions in a PEM fuel cell?
I understand in a fuel cell, that oxidation occurs at the anode where hydrogen gas is split into hydrogen ions and electrons, the former of which travel through the electrolyte. Then, at the cathode, ...
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What is mAh/g Specific capacity?
In battery chemistry I've been reading about specific capacities of various electrochemical cells as $\pu{mAh/g}$. For example, in one article it says the specific capacity of the system is $\pu{75 ...
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Why are ions in a mass spectrometer accelerated through electric plates? [closed]
I was reading an article on the AP Chemistry course in Khan Academy about mass spectrometry, which had this:
... ions are then accelerated through electric plates and subsequently deflected by a ...
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Are electrodes in an electrolysis unique for every electrolyte or can any random electrode be used with an electrolyte during electrolysis
For example, during the electrolysis of water, platinum electrodes are used, why can't I use any other electrode as long as they are conductors? why does some electrolysis require specific electrodes ...
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Why does lead gains electrons in the cathode? [closed]
In lead(II) bromide electrolysis, lead is attracted to the cathode and gains electrons. Why does it gain electrons when losing them would be easier since its charge is +2 meaning it would need to lose ...
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How to turn a copper/zinc penny battery rechargeable?
I just saw the copper+zinc+vinegar battery also known as "penny battery" and I thought it would be perfect to make at home since I don't know anything about chemistry.
In the wikipedia page ...
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Where is the LITHIUM in NMC Cathode?
This maybe a noob question, but regarding NMC Cathodes, it is said that 33% each of Ni, Mn and Cobalt. So where is the LITHIUM supposed to be if all Ni Mn and Co already make up 100%?
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What metals are safe to use as electrodes when doing electrolysis of water (I am trying to produce hydrogen gas)
I am going to be a DC power converter (with fairly high voltage and amps) to turn water into hydrogen (and oxygen) gases. However I have a few questions about the safety of this process.
What ...
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Would laying an atom thick piezoelectric material near a heat source generate current? [closed]
From what I’ve read, a piezoelectric material (like quartz) generates current from squeezing the molecule lattice and deforming it to make the positively charged atoms on one side and the negatively ...
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Why aren't electrolytic cells usually separated?
Galvanic cells need to be separated so that electrons will be forced to move through the external circuit, but I was wondering why electrolytic cells are usually not kept separated but rather as a ...
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Zn galvanic cell without electrolyte?
I performed a classical experiment with Zinc-Copper galvanic cell. The zinc electrode was made from pure zinc wire, the copper electrode was made from pure copper wire, the container was a glass ...
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Hydrogen safety during electro-chemical machining
I'm interested in doing some experiments with electro-chemical machining in my shop. The process involves running electricity through an electrolyte (salt water) to break down a metal anode (aluminum/...
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what are the differences between reversible cells and rechargeable cells?
My chemistry textbook says daniel cells are reversible, but not rechargeable.
Why is it that all reversible cells are not rechargeable?
Are all rechargeable cells reversible? why/why not?
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True or false: "A used AA battery contains fewer moles of electrons than a new AA battery."
I recently took a Gen. Chem. 2 exam that contained this question. I answered false, but my professor said the answer is true. My reasoning was that any electrons that leave the anode end up at the ...
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Size and maximal power output of a battery of electrochemical reactions
For a battery working and chargeable on electrochemical reaction, how does the size of the battery affect its maximal power output?
Specifically, With any chemicals/materials available and current ...
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Hydrated electrons produced by radiation vs electrons from electrostatic charge: are they equally reactive?
One of the species generated in water or aqueous solutions by the ionizing radiations are free electrons that quickly become "hydrated" or "aqueous electrons" (see for example this ...
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How to find the angle of emission of an X-ray during impact of accelerated cathode rays?
X rays are produced when accelerated cathode rays strike a metal target or a metal anode.
How can we find the angle at which the X-ray is emitted from the metal anode or the target when the cathode ...
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What makes up the conduction band?
Prologue/Rant about online classes
We have been taught the electron sea model to explain metallic bonding and conduction of electricity by metals. Then out of the blue, the band theory was introduced, ...
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Why does it so long for a Lithium-ion battery to be charged from 98% to 100%? [closed]
Why does it so long for an Lithium-ion battery to be charged from 98% to 100%?
It is not even comparable to the effort I exerce to pump my bike tires from 95 psi to (the minimally usable) 100 psi. ...
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What is the optimal voltage for storing a 3.7 V lithium polymer battery?
According to this website, storing a lithium polymer (LiPo) battery/cell at around 40% capacity would be more beneficial for the lifespan of the LiPo cell comparing storing the battery at 100% ...
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Why do batteries drain so quickly if they are forced to draw more current than they normally do?
When a battery is pushed to use twice the current it normally does, it lasts for less than half as long before dying...
In fact, batteries often come with a 'C' rating that gives you an idea of how ...
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Can chemical energy from food be stored in a battery? [closed]
Suppose you built a machine that digested food in a similar way as humans do. Would it be possible, in principle, to extract the chemical energy from the digested food, turn it into electricity, and ...
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How do ions conduct electricity? [closed]
I mean to ask what do ions actually do while conducting electricity?
Do they simply take up the electrons and transport it?
If it is so, I do not understand how anions can take up more electrons if ...
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Is electrical work equal to the change in enthalpy or internal energy?
A $\pu{0.5 A}$ current from a $\pu{20 V}$ supply is passed through a water sample. $\pu{0.9 g}$ of water is vapourised at $p = \pu{1 atm}$ and $T = \pu{373 K}$. Calculate $\Delta U$ and $\Delta H$ for ...
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A gram of salt added to pure (distilled) water introduces around $2 \times 10^{22}$ ions? [closed]
I am currently studying Practical Electronics For Inventors, Fourth Edition, by Scherz and Monk. Chapter 2.5.2 Resistivity and Conductivity, claims the following:
Adding an ionic compound in the ...
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Why is distilled water such a poor conductor of electricity?
Water is composed of hydronium ions and hydroxide ions. Since ions do conduct electricity, why is distilled water such a poor conductor of electricity?
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Does voltage or current matter most when setting up an efficient water electrolyzer? [closed]
I am setting up a homemade water electrolyzer for producing hydrogen gas, which will solely be used by myself for experimental purposes, and have heard the wattage used has a large part to play in ...
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Are there ionic solids that conduct electricity?
We are taught in school that ionic substances don't conduct electricity, and when they do, it is either because they are in a molten state or because they are in solution. I understand these concepts.
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Oxidative phosphorylation analogue
Does the salt bridge in galvanic cells resemble the ATP pump in the inner mitochondrial membrane? And if yes than did someone use this pH difference in harvesting this energy?
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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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Electric fields in a galvanic cell
I have read hat there is two types of electric fields exist in galvanic cell.I understand E because of charges accumulated on electrodes but what about other E -field? What does cause this field and ...
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General Oxidant - Reductant Battery
In general, is it true that if I connect an aqueous oxidant to an aqueous reductant via a wire then a current flows along the wire? In particular, does current flow in the following scenario?
Imagine ...
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Amperage for the electrolysis of water?
I am electrolysing water using several different potential catalysts for my eight grade science fair project. The electrolysis will be running at 2 to 2.5
volts over nickel electrodes, as I do not ...
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What is the safest way to hook up car battery jump cables and why? [closed]
I know that when both connecting and disconnecting battery jumper cables between two car batteries there is a prescribed safe way to do it. I can never remember the correct way because I can’t ...
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Stritations in a discharge tube
I am reading about A cathode ray discharge tube and I still do not fully understand why that as you keep on lowering the pressure in the chamber it creates striations, Faraday's dark space and Crooke'...
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What happens when two galvanic cells are placed in series
I understand how a single galvanic cell works, and the relation of equilibrium and the Nernst equation.
But this appears to contradict the higher voltage in a series configuration because it ...
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Salt Bridge for Microbial Fuel Cell: Full or Partly Full?
I'm making a microbial fuel cell out of benthic mud and salt water in containers. My salt bridge will be made of agar and table salt solidified in PVC pipes. Does the salt bridge connecting the anode (...
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Two cells are connected in series. If x g of silver are deposited in cell 1, what volume of oxygen is given off in cell 2? [closed]
I got the answer correct but I'm pretty sure my methodology was wrong. How would you solve such a question?
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What are we seeing in this AC salt-water copper-wire experiment?
There's a highly watched video on YouTube by "ElectroBoom" on the effects of passing AC (not DC) current through salt water. The water gets cloudy and at the end of the video we can see one of the ...
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Would an explosion of an electrically charged material be more powerful than if it were not charged?
I was recently reading a book titled "Hitler's Suppressed and Still Secret Weapons, Science and Technology". I came across this book because I saw it referenced by someone on another site. The book's ...
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How to measure the electrical conductivity of a substance? [closed]
Suppose you are given these substances:
$\ce{NaOH(aq)}$
$\ce{HCl(aq) }$
$\ce{C6H12O6(aq) }$
$\ce{NH3(l)}$
Are there rules to figure out how conductive each compound is? Is it based on ...
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Can running water carry an electrical current indefinitely, and for long distances?
Okay, not a scientist, but doing a writing project that requires a little knowledge. My question is: If there's a constant source generating enough energy into running water (like a stream, surrounded ...
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Is electrolysis with AC current possible? [duplicate]
Optimizing everything else, would efficient electrolysis be possible with AC current? Most sources suggest to use DC, but can the water still be split/disassociated with AC?
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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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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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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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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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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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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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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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