Question

XeF₆ on partial hydrolysis gives a compound X, which has square pyramidal geometry ‘X’ is

• A. XeO₃
• B. XeO₄
• C. XeOF₄
• D. XeO₂F₂

Answer 1

The Correct Option is C

1. Write the Reaction for Partial Hydrolysis of XeF₆
Partial hydrolysis means that not all fluorine atoms are replaced by oxygen atoms from water. A general reaction will be of the form:
$$ XeF_6 + H_2O \rightarrow \text{Product} $$

2. Determine Possible Hydrolysis Products
We need to find a product which has square pyramidal geometry.

3. Consider XeO₃
$XeO_3$ is formed by complete replacement of F by O:
$$ XeF_6 + 3H_2O \rightarrow XeO_3 + 6HF $$
To determine the geometry of $XeO_3$, we need to consider the VSEPR theory.
The central atom is Xe. The number of valence electrons around Xe is 8. There are three oxygen atoms around, therefore there are three bond pairs, with one lone pair present.
The geometry is thus pyramidal.

4. Consider XeO₄
$XeO_4$ has Xe as the central atom. There are 8 valence electrons around Xe. There are four oxygen atoms around. There are thus four bond pairs and 0 lone pairs. The geometry is tetrahedral.

5. Consider XeOF₄
In $XeOF_4$, Xe is the central atom. There are 8 valence electrons around Xe. There are four fluorine atoms and one oxygen around Xe. There are five bond pairs with one lone pair around Xe.
The shape of $XeOF_4$ is square pyramidal because the lone pair occupies one of the octahedral positions (usually trans to the double-bonded oxygen in similar compounds), giving a square pyramidal structure.
The partial hydrolysis reaction would be:
$$ XeF_6 + H_2O \rightarrow XeOF_4 + 2HF $$

6. Consider XeO₂F₂
In $XeO_2F_2$, Xe is the central atom. There are 8 valence electrons around Xe. There are two fluorine atoms and two oxygen around Xe. There are four bond pairs with one lone pair around Xe.
The structure has a seesaw geometry.

7. Identify the Compound with Square Pyramidal Geometry
$XeOF_4$ has a square pyramidal geometry.

Final Answer:
(C) $XeOF_4$

Answer 2

When XeF₆ undergoes partial hydrolysis, it forms XeOF₄, which has a square pyramidal geometry. This is due to the replacement of some fluoride ions with oxygen atoms during hydrolysis, resulting in a square pyramidal structure.

So, the correct answer is (C) : XeOF₄.