Question

Consider the following standard electrode potential $\left( {{E}^{{}^\circ }} \right)$in volts in aqueous solution:

Element	${{M}^{3+}}/M$	${{M}^{+}}/M$
Al	$-1.66$	$+0.55$
Tl	$+1.26$	$-0.34$

Based on these data, which of the following statements is correct?
A. $T{{l}^{+}}$ is more stable than $A{{l}^{3+}}$
B. $T{{l}^{+}}$ is more stable than $A{{l}^{+}}$
C. $A{{l}^{+}}$ is more stable than $A{{l}^{3+}}$
D. $T{{l}^{3+}}$ is more stable than $A{{l}^{3+}}$

Answer 1

In electrochemistry, we basically deal with study of the relationship between the electrical energy and chemical energy. In electrochemical reactions, the chemical reactions require the input or generation of electric currents.

Complete step-by-step answer: Standard electrode potential is used to measure the individual potential of an electrode at a standard state and pressure. If the value of standard reduction potential increases then it becomes easier for the elements to get reduced.
In this question, standard reduction potential is given because ${{M}^{3+}}$ is gaining three electrons to form a metal $M$ and ${{M}^{+}}$ is gaining one electron to form a metal $M$ . This proves that standard reduction potential is given in this question.
The more the value of standard reduction potential is negative, the more that element is stable.
From the above data, as we can see that in ${{M}^{+}}/M$ , the $T{{l}^{+}}$ has more negative value than $A{{l}^{+}}$, that means the standard reduction potential of $T{{l}^{+}}$is more than that of $A{{l}^{+}}$.
Hence, we can say that the $T{{l}^{+}}$ is more stable than $A{{l}^{+}}$
The more the value of standard reduction potential is negative, the more that element is stable.
From the above data, as we can also see that in ${{M}^{3+}}/M$ , the $A{{l}^{3+}}$ has more negative value than $T{{l}^{3+}}$, that means the standard reduction potential of $A{{l}^{3+}}$is more than that of $T{{l}^{3+}}$.
Hence, we can say that the $A{{l}^{3+}}$ is more stable than $T{{l}^{3+}}$

Therefore, the correct option is D.

Note: It is to note that in an electrochemical cell, a spontaneous reaction occurs that results in the conversion of chemical energy into electrical energy. Spontaneous chemical reaction occurs on its own. Electrochemical cells are of two types: galvanic cells and electrolytic cells.
The negative the value of standard reduction potential, the more it will become stable.