Question

For the electrochemical cell, $M\mid {M^ + }\parallel {X^ - }\mid X$, ${E^ \circ }_{{M^ + }/M} = 0.44V$ and ${{\mathbf{E}}^ \circ }_{{\mathbf{X}}/{\mathbf{X}}} = {\mathbf{0}}.{\mathbf{33}}\;{\mathbf{V}}$. From this data we can deduce that__________.
A $M + X \to {M^ + } + {X^ - }\;$is the spontaneous reaction
B ${M^ + } + {X^ - } \to M + X\;$is the spontaneous reaction
C ${E_{cell}} = 0.77\;V$
D ${E_{cell}} = - 0.77\;V$

Answer 1

In redox reaction we can see that both oxidation and reduction occur. These reaction occur when electrons are transferred from a substance which is oxidized to the on which is being reduced. The reductant is the substance that loses electrons and is oxidized in the process; the oxidant is the species that gains electrons and is reduced in the process. It consists of two electron conductors which are separated. This separation occurs by an ionic conductor and linked by an electron conductor.

Complete step-by-step answer: Electrolyte is called as the ionic conductor. It is where we can find the ions which are present in the solution that needs to go under the electrochemical process. Electrodes are the conductors which are separated by the electrolyte. The electron conductor used to link the electrodes is often a metal wire, such as copper wiring. When we talk about electrochemical cells, then we must know that there are two fundamental types of electrochemical cell: galvanic and electrolytic.
Galvanic cell- it converts chemical potential energy to electric energy. This happens due to spontaneous redox reactions which produce an electron flow
Electrolytic call- these are driven by an external source. This source is of non spontaneous redox reaction
For the above reaction:
$M\mid {M^ + }\parallel {X^ - }\mid X$
${E^ \circ }_{{M^ + }/M} = 0.44V$
The electrode reduction potential of ${E^ \circ }_{{M^ + }/M}$is greater than${E_{{X^ - }/X}}$. Thus the reduction is known to occur of ${M^ + }$
For reaction- ${M^ + } + {X^ - } \to M + X$ ${E^ \circ }_{cell} = 0.44V - 0.33V = 0.11V$
Finally, as the emf of the cell is positive. This means that the reaction is spontaneous.

Thus option $B$ is correct.

Note: In galvanic cells, hydrogen is oxidised at anode by transferring electrons to anode and oxygen gets reduced at the cathode as cathode accepts electrons from cathode. There are ions produced of hydrogen and hydroxyl ions. These ions combine in solution to form the final product which is water. The reaction can also be reversed: water can be decomposed into hydrogen and oxygen by the application of electrical power in an electrolytic cell.