Question

Choose the correct choice containing true statements regarding $PCI_5$.
(i) PCI, is prepared by the reaction of white phosphorus with excess of dry chlorine. 
(ii) The complete hydrolysis of PCI, gives phosphoric acid.  
(iii) PCI, has square pyramidal structure in gaseous phase. 
(iv) All the five bonds in PCI, molecule are equivalent.

• A. ii and iii
• B. i and iii
• C. iii and iv
• D. ii and iv
• E. i and ii

Answer 1

Answer: (E)

Statements:

1. $PCl_5$ is prepared by the reaction of white phosphorus with excess of dry chlorine.
2. The complete hydrolysis of $PCl_5$ gives phosphoric acid.
3. $PCl_5$ has square pyramidal structure in gaseous phase.
4. All the five bonds in $PCl_5$ molecule are equivalent.

Correct Answer: i and ii

Explanation:

• Statement (i) is correct: White phosphorus reacts with excess dry chlorine to form phosphorus pentachloride.
• Statement (ii) is correct: Complete hydrolysis of $PCl_5$ gives phosphoric acid ($H_3PO_4$).
• Statement (iii) is incorrect: $PCl_5$ has a trigonal bipyramidal geometry in gaseous and liquid phases, not square pyramidal.
• Statement (iv) is incorrect: In the trigonal bipyramidal structure, the axial and equatorial bonds are not equivalent.