Question

The electrochemical equivalent for zinc (atomic weight=65.4) is:
A.\[3.4\times {{10}^{-4}}\]
B.\[3.8\times {{10}^{-4}}\]
C.\[3.6\times {{10}^{-4}}\]
D.None of these

Answer 1

Hint: The electrochemical equivalent which is sometimes abbreviated as Z, of a chemical element is defined as the mass of that element transported by 1 coulomb of electric charge. The electrochemical equivalent of an element is measured with a device called voltameter.
We can solve this question by keeping the following formula in mind.
\[z=\dfrac{molar mass}{nf\times F}\]
Where z is the electrochemical equivalent, F is faraday’s constant and nf is the n factor.

Complete step by step answer:
It is given to us that,
Molar mass of zinc is 65.4 g/mol
N factor for zinc is 2
Faraday’s constant F is 96500 C/mol.
So in order to solve the problem the Formula used: \[z=\dfrac{molar mass}{nf\times F}\]
Now after substituting the given values in the formula we get,
\[Z=\dfrac{65.4}{2\times 96500}\]
\[Z=3.4\times {{10}^{-4}}\]

Hence, the correct option is option A which is \[Z=3.4\times {{10}^{-4}}\].


Note:
A voltameter or coulometer is defined as a scientific instrument used for measuring quantity of electricity through electrolytic action. The SI unit of quantity of electricity is given by the coulomb. The voltmeter should not be confused with a voltmeter as voltmeter is a device which measures electric potential and the SI unit for electric potential is the volt which are very different from each other.
Faraday discovered that when the same amount is passed through different electrolytes or elements which are connected in series, the mass of the substance liberated or deposited at the electrodes in grams is directly proportional to their chemical equivalent or the equivalent weight. This is known as the second law of Faraday.