Chemistry:Electrochemical equivalent
In chemistry, the electrochemical equivalent (Eq or Z) of a chemical element is the mass of that element (in grams) transported by a specific quantity of electricity, usually expressed in grams per coulomb of electric charge.[1] The electrochemical equivalent of an element is measured with a voltameter.
Definition
The electrochemical equivalent of a substance is the mass of the substance deposited to one of the electrodes when a current of 1 ampere is passed for 1 second, i.e. a quantity of electricity of one coulomb is passed.
The formula for finding electrochemical equivalent is as follows:
- [math]\displaystyle{ Z = M/q }[/math]
where [math]\displaystyle{ M }[/math] is the mass of substance and [math]\displaystyle{ q }[/math] is the charge passed. Since [math]\displaystyle{ q=It }[/math], where [math]\displaystyle{ I }[/math] is the current applied and [math]\displaystyle{ t }[/math] is time, we also have
- [math]\displaystyle{ Z=M/It }[/math]
Eq values of some elements in kg/C
| Element | Electrochemical equivalent |
|---|---|
| Silver (Ag) | 1.118×10^(-6)
0.000118gm/c |
| Copper (Cu) | 3.295×10^(-7) |
| Gold (Au) | 6.812×10^(-7) |
| Iron (Fe) | 2.894×10^(-7) |
| Zinc (Zn) | 3.389×10^(-7) |
| Hydrogen (H2) | 1.044×10^(-7) |
| Sodium (Na) | 2.387×10^(-7) |
| Potassium (K) | 4.055×10^(-7) |
| Oxygen (O2) | 8.28×10^(-8) |
| Aluminum (Al) | 9.36×10^(-8) |
References
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