Question

Which from following statements is true for group 16 elements?

• A. All elements of this group form $\text{EO}_2$ type oxides.
• B. It includes all the nonmetals.
• C. Oxides of all elements of this group are gaseous at room temperature.
• D. Reducing properties of dioxides of this group element decreases form $\text{SO}_2$ to $\text{TeO}_2$.

Hint:

Remember the classic d-block and p-block oxide rule: For a given oxidation state down a group, the heavier element's oxide tends to be a solid and behaves more as an oxidizing agent, while the lighter element's oxide ($\text{SO}_2$) behaves as a reducing agent.

Answer 1

The Correct Option is D

Step 1: Frame the question.
We must test four statements about Group 16 (the chalcogens: O, S, Se, Te, Po) and keep the one that is true.
Step 2: Test statement (1).
It claims every element forms an $\text{EO}_2$ oxide. Oxygen itself cannot form an $\text{EO}_2$ oxide with itself, so this fails.
Step 3: Test statement (2).
It claims the group is all nonmetals. But Te is a metalloid and Po is a metal, so the group is not entirely nonmetallic. False.
Step 4: Test statement (3).
It claims all the oxides are gases. $\text{SO}_2$ is a gas, but $\text{SeO}_2$ and $\text{TeO}_2$ are solids at room temperature. False.
Step 5: Analyse the redox trend for statement (4).
In $\text{SO}_2$, sulfur is $+4$ and readily oxidises to the stable $+6$ state, so $\text{SO}_2$ is a good reducing agent.
Step 6: Apply the inert pair effect.
Going down the group the $+4$ state becomes more stable relative to $+6$, so $\text{TeO}_2$ resists oxidation and even acts as an oxidising agent. Hence the reducing power of the dioxides falls from $\text{SO}_2$ to $\text{TeO}_2$. Statement (4) is true.
\[ \boxed{\text{Statement (4) is correct}} \]