Question

Given below are two statements:
Statement (I): The oxidation state of an element in a particular compound is the charge acquired by its atom on the basis of electron gain enthalpy consideration from other atoms in the molecule.
Statement (II): $p\pi$-$p\pi$ bond formation is more prevalent in second period elements over other periods.
In the light of the above statements, choose the {most appropriate answer from the options given below:

• A. Both Statement I and Statement II are incorrect
• B. Statement I is correct but Statement II is incorrect
• C. Both Statement I and Statement II are correct
• D. Statement I is incorrect but Statement II is correct

Answer 1

The Correct Option is D

Let's analyze both statements to determine their correctness.

1. Statement (I): The oxidation state of an element in a particular compound is the charge acquired by its atom on the basis of electron gain enthalpy consideration from other atoms in the molecule.
   • The definition given in Statement I is incorrect. The oxidation state of an element in a compound is based on the formal charge concept, assuming electrons are transferred completely, rather than on electron gain enthalpy.
   • Oxidation states are typically assigned by assuming that bonds between different elements are 100% ionic.
2. Statement (II): \(p\pi-p\pi\) bond formation is more prevalent in second period elements over other periods.
   • This is a correct statement. Elements in the second period (like Carbon, Nitrogen, and Oxygen) are known for forming multiple bonds such as double and triple bonds, which often involve \(p\pi-p\pi\) overlap.
   • The smaller atomic size and high electronegativity of these elements facilitate efficient \(p\pi-p\pi\) overlap, making such bond formations more prevalent in second period elements compared to those in higher periods.

Considering the analysis for both statements, the most appropriate choice is: Statement I is incorrect but Statement II is correct.

Answer 2

Explanation:

1. Statement (I): Incorrect. - The oxidation state of an element is not determined based on electron gain enthalpy. Instead, it is based on the number of electrons lost, gained, or shared during bond formation.

2. Statement (II): Correct. - \( p\pi-p\pi \) bond formation is more common in second-period elements (e.g., \( C, N, O \)) due to their small size and effective overlap of \( p \)-orbitals, which diminishes in larger elements from lower periods.

Final Answer is Option (4).