# Electrochemical equivalent

The Electrochemical equivalent, sometimes abbreviated Eq or Z, of a chemical element is the mass of that element (in grams) transported by 1 coulomb of electric charge. 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:

$Z=M/q$

where $M$  is the mass of substance and $q$  is the charge passed. Since $q=It$ , where $I$  is the current applied and $t$  is time, we also have

$Z=M/It$

## Eq values of some elements in kg/C

Element Electrochemical equivalent
Silver (Ag) 1.118×10^(-6)
Copper (Cu) 3.295×10^(-7)
Gold (Au) 6.812×10^(-7)
Iron (Fe) 2.894×10^(-7)
Zinc (Zn) 1.58×10^(-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^(-7)