In which one of the given formulae of xenon compounds there are five a-bonds and three p-bonds in it? (A) XeFO (B) XeF2O2 (C) XeF3O2 (D) XeF2O3

To determine which of the given xenon compounds contains five sigma (σ) bonds and three pi (π) bonds, we need to analyze the bonding structure of each compound. Let's break down the options one by one.

Understanding Bond Types

In molecular chemistry, bonds can be classified as sigma (σ) or pi (π) bonds. Sigma bonds are formed by the head-on overlap of atomic orbitals and are the first bonds formed between two atoms. Pi bonds, on the other hand, are formed by the side-to-side overlap of p orbitals and are typically found in double and triple bonds.

Analyzing Each Compound

• A) XeFO: This compound consists of one xenon atom bonded to one fluorine atom and one oxygen atom. The bonding involves one σ bond with fluorine and one σ bond with oxygen. There are no double or triple bonds, so there are no π bonds. Total: 2 σ bonds, 0 π bonds.
• B) XeF2O2: In this compound, xenon is bonded to two fluorine atoms and two oxygen atoms. The structure typically involves two σ bonds with fluorine and two σ bonds with oxygen. If we assume that the oxygen atoms are bonded with single bonds, there are no π bonds. Total: 4 σ bonds, 0 π bonds.
• C) XeF3O2: Here, xenon is bonded to three fluorine atoms and two oxygen atoms. The bonding would involve three σ bonds with fluorine and two σ bonds with oxygen. If we consider that the oxygen atoms are involved in double bonds, we could have π bonds. However, this compound does not typically have a structure that supports five σ bonds and three π bonds. Total: 5 σ bonds, possibly 0-2 π bonds.
• D) XeF2O3: In this compound, xenon is bonded to two fluorine atoms and three oxygen atoms. The bonding can involve two σ bonds with fluorine and three σ bonds with oxygen, where the oxygen atoms can form double bonds. This configuration can lead to a total of 5 σ bonds and 3 π bonds if we assume that each oxygen forms a double bond with xenon. Total: 5 σ bonds, 3 π bonds.

Conclusion on the Correct Option

Based on the analysis, the compound that contains five sigma bonds and three pi bonds is D) XeF2O3. This compound's structure allows for the formation of multiple bonds with oxygen, leading to the required bond count.

Visualizing the Structure

To visualize this, imagine xenon at the center with two fluorine atoms and three oxygen atoms surrounding it. The oxygen atoms can form double bonds with xenon, contributing to the π bonds, while the fluorine atoms contribute to the σ bonds. This arrangement satisfies the criteria of having five σ bonds and three π bonds.

Understanding the bonding in xenon compounds is crucial, as it illustrates the unique chemistry of noble gases and their ability to form stable compounds under certain conditions.