Question

$\text{Li}$ occupies higher position in the electrochemical series of metals as compared to $\text{Cu}$since:
A. The standard reduction potential of $\text{L}{{\text{i}}^{+}}/\text{Li}$ is lower than that of$\text{C}{{\text{u}}^{+2}}\text{/Cu}$.
B. The standard reduction potential of $\text{C}{{\text{u}}^{+2}}\text{/Cu}$is lower than that of$\text{L}{{\text{i}}^{+}}/\text{Li}$.
C. The standard oxidation potential of $\text{Li/L}{{\text{i}}^{+}}$ is lower than that of$\text{Cu/C}{{\text{u}}^{+2}}$.
D. $\text{Li}$is smaller in size as compared to$\text{Cu}$.

Answer 1

Hint: Copper is metal with symbol$\text{Cu}$and atomic number 29.The common oxidation states of $\text{Cu}$is +1 and +2. The Electron Configuration of $\text{Cu}$is $\text{1}{{\text{s}}^{2}}\text{2}{{\text{s}}^{2}}\text{2}{{\text{p}}^{6}}\text{3}{{\text{s}}^{2}}\text{3}{{\text{p}}^{6}}\text{4}{{\text{s}}^{1}}\text{3}{{\text{d}}^{10}}$ . Lithium is an alkali metal $\text{Li}$ with atomic number 2. The oxidation state of $\text{Li}$ is +1. The electronic configuration of $\text{Li}$ is$1{{\text{s}}^{2}}2{{\text{s}}^{1}}$.

Complete step by step answer:
Firstly, we should know what electrochemical series is- Electrochemical series is an activity series which has the arrangement of elements in increasing order of their electrode potential values. This series is based on measuring the potential of electrodes versus standard hydrogen electrodes (SHE). In electrochemical series, the elements are arranged in increasing order of their standard reduction potentials. By electrochemical series
-The values of standard reduction potential of $\text{L}{{\text{i}}^{+}}/\text{Li}$is -3.05 volts. Lithium is a strong reducing agent as it belongs to alkali metals it likes to easily lose 1 electron to give inert gas configuration that is why $\text{L}{{\text{i}}^{+}}/\text{Li}$have negative reduction potential.
- The values of standard reduction potential of $\text{C}{{\text{u}}^{+2}}\text{/Cu}$is +0.034 volts.
- The values of standard oxidation potential of$\text{Li/L}{{\text{i}}^{+}}$ is +3.05 volts.
- The values of standard oxidation potential of $\text{Cu/C}{{\text{u}}^{+2}}$is -0.34 volts.
As per reduction potential $\text{L}{{\text{i}}^{+}}/\text{Li}$has less value than$\text{C}{{\text{u}}^{+2}}\text{/Cu}$. So, in increasing order of reduction potentials $\text{L}{{\text{i}}^{+}}/\text{Li}$lies above than$\text{C}{{\text{u}}^{+2}}\text{/Cu}$ .
The answer is $\text{Li}$ occupies higher position in the electrochemical series of metals than $\text{Cu}$as the standard reduction potential of $\text{L}{{\text{i}}^{+}}/\text{Li}$ is lower than that of$\text{C}{{\text{u}}^{+2}}\text{/Cu}$, which is option A.
There is no connection of sizes with electrode potentials. So, neglect option D.

Additional Information:
Uses of Copper:
(1) Copper alloys used in jewellery. Copper is moulded metal that is added to precious metals to improve their elasticity, flexibility, colour, and resistant to corrosion.
(2) Copper wire and piping is the most common use i.e. in building materials in the plumbing and electrical industries.
Uses of Lithium:
(1) Lithium is a component of battery electrodes and electrolytes, because of its high electrode potential.
(2) Lithium has been found in assisting the perfection of silicon nano-welding of the electronic components for electric batteries.

Note: There is a difference between oxidation potential and reduction potential. Oxidation is loss of electrons like $\text{Cu/C}{{\text{u}}^{+2}}$and Reduction is gain of electrons like$\text{C}{{\text{u}}^{+2}}\text{/Cu}$. We generally take Reduction potential of elements while solving the questions of electrochemistry that is SHE at standard terms and conditions. So, we have to use Reduction potential only whether the element is undergoing oxidation or reduction, till it is mentioned to use oxidation potential of the element.