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Electrochemistry — Chemistry STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceChemistryElectrochemistry3 Marks
Question
Explain the structure and function of salt bridge of molten galvanic cell.
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Answer

A salt bridge is an U-shaped glass tube containing saturated agar-agar gel with $KCl , KNO _3, NH _4 Cl$ etc. It completes the electrical circuit and maintains the electrical neutrality of both the earth cells. After the release of electrons, the excess positive charge $\left( Zn ^{2+}\right)$ present at anode is neutralized. Anions $\left( Cl ^{-}, NO _3{ }^{-}\right.$moves through the salt bridge towards anode and similarly, to neutralize excess negative charge $\left( SO _4{ }^{2-}\right)$ on the cathode, the cations $\left( K ^{+}\right.$, $NH _4{ }^{+}$) present in salt bridge moves towards the cathode. Before the movement of mentioned ions, the reaction and the flow of electricity stops.

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