Question

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: Beryllium has less negative value of reduction potential compared to the other alkaline earth metals
Reason R: Beryllium has large hydration energy due to small size of \(Be ^{2+}\) but relatively large value of atomization enthalpy
In the light of the above statements, choose the most appropriate answer from the options given below

• A. Both $A$ and $R$ are correct and $R$ is the correct explanation of $A$
• B. $A$ is not correct but $R$ is correct
• C. Both $A$ and $R$ are correct but $R$ is NOT the correct explanation of $A$
• D. $A$ is correct but $R$ is not correct

Hint:

Reduction potential is influenced by hydration energy, ion size, and atomization enthalpy. Smaller ions like \(Be^{2+}\) have higher hydration energy, stabilizing the ion in aqueous solutions.

Answer 1

The Correct Option is A

Beryllium has a less negative reduction potential compared to other alkaline earth metals (AEM). This is because of:
• High hydration energy: Due to the small size of the Be2+ ion, the hydration energy is very large, which stabilizes the ion in aqueous solutions.
• Large atomization enthalpy: Beryllium has strong metallic bonding due to its small atomic size, which increases its atomization enthalpy. These factors reduce the tendency of beryllium to get reduced, leading to a less negative
reduction potential.
Since the reason (R) explains why beryllium has a less negative reduction potential, both A and R are correct, and R is the correct explanation of A.