Electrochemistry
Electrochemistry is the study of the production of
electricity from the energy released during spontaneous
chemical reactions and the use of electrical energy
to bring about non-spontaneous chemical
transformations.
Batteries and fuel cells
convert chemical energy into electrical energy and are
used on a large scale in various instruments and
devices. The transmission of
sensory signals through cells to brain and vice versa
and communication between the cells are known to
have electrochemical origin.
Galvanic Cell /Voltaic Cell
`Zn(s) + Cu^{2+} SO_4^{2-} (aq) rightarrow Cu(s) + Zn^{2+} SO_4^{2-} (aq)`
`Zn (s) rightarrow Zn^{2+} + 2e^-`
`Cu^{2+}(aq) + 2e^- rightarrow Cu(s)`
The cell converts the chemical energy liberated
during the redox reaction to electrical energy and has an electrical
potential equal to `1.1 V` when concentration
of `Zn^{2+}` and `Cu^{2+}` ions is unity `(1 mol dm^{–3)}`.
Such a device is called a galvanic or a
voltaic cell
`Zn(s) + Cu^{2+}(aq) → Zn^{2+}(aq) + Cu(s)`
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| Daniell cell having electrodes of zinc and copper dipping in the solutions of their respective salts. (Image credit: NCERT) |
Amazing notes 👍👍👍
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