Question

Given below are two statements:
Statement (I) : Oxygen being the first member of group 16 exhibits only –2 oxidation state.
Statement (II) : Down the group 16 stability of +4 oxidation state decreases and +6 oxidation state increases.
In the light of the above statements, choose the most appropriate answer from the options given below:

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

Answer 1

The Correct Option is C

To determine the correctness of the given statements, let's analyze each one based on our understanding of Chemistry, specifically the oxidation states of Group 16 elements. 

1. Statement (I): Oxygen being the first member of group 16 exhibits only –2 oxidation state.
   • Oxygen is indeed the first member of Group 16 in the periodic table. It commonly exhibits an oxidation state of –2 in most of its compounds. However, it does exhibit other oxidation states under certain conditions. For example, in peroxides like \(\text{H}_2\text{O}_2\), oxygen has an oxidation state of –1, and in compounds like \(\text{OF}_2\), oxygen has an oxidation state of +2.
   • Therefore, Statement (I) is incorrect due to this variability in oxidation states.
2. Statement (II): Down the group 16 stability of +4 oxidation state decreases and +6 oxidation state increases.
   • In Group 16, which includes elements like Oxygen, Sulfur, Selenium, Tellurium, and Polonium, the stability of oxidation states varies with different elements.
   • As we move down the group from Oxygen to Polonium, the ability of elements to exhibit a +6 oxidation state generally decreases due to the inert pair effect, which is more pronounced in heavier elements. Conversely, in practice, the +4 state is more stable in heavier Group 16 elements like Selenium and Tellurium compared to the +6 state.
   • Therefore, Statement (II) is incorrect. The trend mentioned is reversed in the explanation.

Based on the analysis above, both Statement I and Statement II are incorrect, which makes the correct answer:

Both Statement I and Statement II are incorrect

.

 

Answer 2

Statement I: Oxygen, as the first member of group 16, primarily exhibits an oxidation state of \(-2\) due to its high electronegativity and small size, which favors electron gain rather than loss. However, it can also exist in oxidation states other than \(-2\), such as 0 in molecular oxygen (\(O_2\)), and \(+1\) or \(+2\) in compounds like \(OF_2\) and \(O_2F_2\). Therefore, the statement that oxygen exhibits only a \(-2\) oxidation state is incorrect.

Statement II: In group 16 elements, moving down the group from oxygen to polonium, there is an observed increase in the stability of the \(+4\) oxidation state, while the stability of the \(+6\) oxidation state decreases. This trend is attributed to the inert pair effect, where the tendency of the \(s\)-electrons to remain unpaired increases in heavier elements, making higher oxidation states less stable. Thus, elements like tellurium and polonium prefer to exhibit the \(+4\) oxidation state rather than \(+6\). Hence, the statement that the stability of the \(+4\) oxidation state decreases down the group is also incorrect.

The Correct answer is: Both Statement I and Statement II are incorrect