Question

Identify the correct statements from the following:

• A. In PCl\(_5\), equatorial bonds are longer than axial bonds.
• B. Zinc reacts with dilute nitric acid to give NO\(_2\).
• C. Rhombic sulphur is yellow in colour.
• D. The reaction \( 2SO_2(g) + O_2(g) \xrightarrow{V_2O_5} 2SO_3(g) \) is exothermic.

Hint:

- PCl\(_5\) has a trigonal bipyramidal structure, where axial bonds are longer than equatorial bonds.
- Zinc and dilute HNO\(_3\) produce multiple nitrogen oxides, not just NO\(_2\).
- Rhombic sulfur is the most stable allotrope at room temperature.
- SO\(_2\) to SO\(_3\) oxidation in the Contact Process is catalyzed by V\(_2\)O\(_5\) and is an exothermic reaction.

Answer 1

The Correct Option is D

Step 1: Analyzing Each Statement 
- Statement i: Incorrect. In PCl\(_5\), axial bonds are longer than equatorial bonds due to greater bond repulsions. 
- Statement ii: Incorrect. Zinc reacts with dilute nitric acid to give N\(_2\)O, NO, and NH\(_4\)NO\(_3\), not just NO\(_2\). 
- Statement iii: Correct. Rhombic sulfur is the most stable allotrope and appears yellow in color. 
- Statement iv: Correct. The reaction \( 2SO_2(g) + O_2(g) \xrightarrow{V_2O_5} 2SO_3(g) \) is exothermic and used in the Contact Process for sulfuric acid production. 

Step 2: Conclusion 
- The correct statements are iii and iv, making Option (4) the correct answer.