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doc.madani
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i was wondering what are the chemical reactions involved in producing the electricity, that the batteries provide i.e. the reductant and the oxidant
doc.madani said:i was wondering what are the chemical reactions involved in producing the electricity, that the batteries provide i.e. the reductant and the oxidant
I'm not clear about your OP question: the text doesn't follow the title - dry cells. The purpose of the electrolyte in a dry cell is the same as a 'wet cell' to provide a substance with free ions which can migrate to and from the electrodes. The dry cell doesn't use a liquid electrolyte so it is typically more portable.doc.madani said:what is the purpose of a Potassium Chloride salt bridge, and a ammonium chloride or zinc chloride electrolyte?
As I understand it, electrons are not transferred through the electrolyte all the way from electrode to electrode. Instead, outside of the electrodes, electron motion is limited to the field adjacent the electrode. Only ions are free to move through the electrolyte. See hereAllens said:OK thank you that was very helpful, i would also like to ask where in the battery does the manganese dioxide be reduced (i know the cathode, however i am unsure where the cathode physically is), also could you say the transfer of electrons through the anode to cathode via the electrolytes is called the redox reaction hence generating the electricity to power our devices i.e. torches.
Gokul43201 said:The basic concepts of a voltaic cell are covered nicely here: http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/electrochem.html#c2 (albeit using the example of a Daniel Cell, with Cu and Zn electrodes).
The same general principle applies to all voltaic cells, but in particular, the reactions of the common NH4Cl/MnO2 dry cell are given here: http://library.kcc.hawaii.edu/external/chemistry/everyday_battery.html
The Cl- liberated from the NH4Cl is taken up at the anode, by the oxidation of Zn to ZnCl2. But as such, it is not particularly important to the electrochemistry of the cell.Allens said:"the reduction reaction occurs within the moist paste comprised of ammonium chloride (NH4Cl) and manganese dioxide (MnO2):
2 NH4+ + 2 MnO2 + 2e- ------> Mn2O3 + 2 NH3 + H2O" [source: http://library.kcc.hawaii.edu/external/chemistry/everyday_battery.html ]
i don't understand where the chloride goes in this reaction. Is it simply an spectator ion?
Yes, it's a reasonable summary. Minor points: what you refer to as Enort is actually E0 ("E naught"), and the reduction reaction does not happen "in" the carbon (or graphite) electrode, but rather, at its surface.zinc is oxidized and manganese-dioxide is reduced forming the redox reaction generating an Enort of 1.5 volts, the reduction half reaction occurs in the "paste of MnO2, electrolyte and carbon" and the oxidation half reaction occurs in the anode "Zinc cylinder" (<--- is this statement a "summary" of the reactions occurring within a dry cell battery?)
That's the reduction reaction (or a half-cell reaction). A red-ox reaction is what you get when you combine a reduction reaction with the corresponding oxidation reaction, just like the one I wrote out explicitly above.by the way... 2 NH4+ + 2 MnO2 + 2e- ------> Mn2O3 + 2 NH3 + H2O isn't this reaction the redox reaction or the reduction reaction?
A dry cell battery is a type of electrochemical cell that converts chemical energy into electrical energy. It is commonly used in portable electronic devices such as flashlights, remote controls, and toys.
A dry cell battery works by converting chemical energy into electrical energy through a redox reaction. The chemical reactions involved in a dry cell battery occur between the anode (usually made of zinc) and the cathode (usually made of carbon and manganese dioxide). The electrolyte, which is usually a paste or gel, allows for the movement of ions and completes the circuit.
The main chemical reactions involved in a dry cell battery are the oxidation of zinc at the anode and the reduction of manganese dioxide at the cathode. The electrolyte, usually a mixture of ammonium chloride and zinc chloride, helps to facilitate these reactions.
The electrolyte in a dry cell battery serves two main purposes. First, it provides a medium for the movement of ions between the anode and cathode, allowing for the flow of electricity. Second, it helps to prevent the build-up of hydrogen gas at the anode, which can cause the battery to explode.
Dry cell batteries have several advantages over other types of batteries. They are sealed, which makes them more durable and less prone to leakage. They also have a longer shelf life and can hold their charge for extended periods of time. Additionally, they are relatively inexpensive and can be easily replaced when they run out of power.