Question

What is the main principle involved in voltaic cells?
(a)- Conversion of chemical energy into heat energy
(b)- Conversion of heat energy into electrical energy
(c)- Conversion of chemical energy into electrical energy
(d)- Conversion of electrical energy into chemical energy

Answer 1

The voltaic cell is also known as galvanic cell and it is basically an electrochemical cell which means that there is a conversion between chemical energy and electrical energy.

Complete step-by-step answer: The voltaic cell is also known as galvanic cell and it is basically an electrochemical cell is a substance in which a redox reaction takes and the redox reaction results in electrical energy. Commonly there are two electrodes that are made up of metals and these electrodes are dipped in their respective salt solutions. A general example is a Zn-Cu cell, in which the zinc electrode acts as the anode and the copper electrode acts as the cathode. The zinc electrode is dipped in zinc sulfate solution and the copper electrode is dipped in copper sulfate solution, and both the solutions are connected by a salt bridge. Both the electrodes are connected by a voltmeter which tells the flow of electrons. So, when the redox reaction starts to take place there is the movement of electrons in the solution, which will create an electric current. The reaction can be written as:
$Zn(s)+C{{u}^{2+}}(aq)\to Z{{n}^{2+}}(aq)+Cu(s)$
In this reaction, there is a flow of two electrons.
So, we can say that the chemical energy is being converted into electrical energy.

Therefore, the correct answer is an option (c).

Note: The Zn-Cu cell is also called a Daniel cell. Mostly the elements of d-block or transition elements are used in the voltaic cell and one factor is due to the difference between the metal ionization energies in water.