Question

Find the total number of pr-d \(\pi\) bonds present in \(\mathrm{XeO}_{4}\).

Short answer

There are 4 pr-d \\(\pi\\) bonds in \\\mathrm{XeO}_{4}\\).

Step-by-step solution

Identify the Central Atom

The central atom in the compound \(\mathrm{XeO}_{4}\) is xenon (Xe), which is surrounded by four oxygen atoms.

Determine the Bond Type

Xenon typically forms covalent bonds with oxygen. In \(\mathrm{XeO}_{4}\), each xenon-oxygen bond is initially assumed to be a sigma bond due to the overlap of sp3 hybridized xenon orbitals with oxygen's p orbitals.

Hybridization and Valence Electrons

Xe is in group 18 with 8 valence electrons. Each oxygen atom needs 2 additional electrons to complete its octet. In total, 8 electrons are needed by four oxygen atoms, resulting in the multiple formation of bonds, including potential \(\pi\) bonds.

Identify \\(\pi\\) Bonds in \\(\mathrm{XeO}_{4}\\)

After forming single sigma bonds, xenon has remaining valence electrons that can participate in \(\pi\) bonding with the oxygen atoms by the lateral overlap of p orbitals on oxygen with d orbitals of xenon, forming pr-d \(\pi\) bonds.

Count the \\(\pi\\) Bonds

Since Xe is forming pr-d \(\pi\) bonds with each oxygen atom, and there are 4 oxygen atoms, the total number of pr-d \(\pi\) bonds is 4.

Key concepts

Xenon Tetraoxide

Xenon tetraoxide, symbolized as \(\text{XeO}_4\), is a chemical compound that consists of xenon as a central atom bonded to four oxygen atoms. This compound showcases the ability of certain noble gases, like xenon, to form stable bonds with other elements, despite being part of Group 18 on the periodic table typically known for their non-reactive nature. In \(\text{XeO}_4\), xenon achieves a full valence shell by forming bonds with oxygen atoms. This interesting behavior challenges the common perception of noble gases being entirely inert and highlights xenon's unique chemistry.

Hybridization

Hybridization is a concept in chemistry where atomic orbitals mix to form new hybrid orbitals. This process is significant as it helps explain the geometry and bonding of molecules. In the case of \(\text{XeO}_4\), xenon undergoes \( sp^3 \) hybridization to bond with the oxygen atoms.

• The \( sp^3 \) hybridization involves one s orbital and three p orbitals mixing to create four equivalent sp³ hybrid orbitals.
• These hybrid orbitals form sigma bonds with the p orbitals of oxygen atoms, contributing to the compound's tetrahedral structure.

While xenon contains d orbitals, the initial bonding involves sp³ hybrid orbitals forming sigma bonds, which may later engage in \( \pi \) bonds through pr-d overlap.

Covalent Bonding

Covalent bonding occurs when two atoms share electrons to achieve a full valence shell. In \(\text{XeO}_4\), covalent bonds are established between xenon and oxygen atoms. This type of bonding is crucial for the stability and formation of \(\text{XeO}_4\).

• Xenon, though a noble gas, has available valence electrons that can participate in covalent bonding with more electronegative oxygen atoms.
• Each of these bonds initially forms as a sigma bond due to head-on overlapping, assuring the strong connectivity between xenon and oxygen.

Once these sigma bonds form, additional interactions leading to \(\pi\) bonds may also occur, enhancing the compound's stability and completing the octets where needed.

Valence Electrons

Valence electrons are the electrons present in the outermost shell of an atom. These are critical in determining an element's bonding capability and reactivity.

• Xenon has 8 valence electrons as it belongs to Group 18 of the periodic table.
• In \(\text{XeO}_4\), these valence electrons are used to form bonds with oxygen atoms, which require 2 electrons each to complete their octet.

This need for completion drives oxygen atoms to form bonds, leading xenon to employ its valence electrons efficiently. Beyond forming standard sigma bonds, xenon's remaining valence electrons can engage in additional bonding interactions, such as forming \( \pi \) bonds, exemplified by the pr-d interactions observed in \(\text{XeO}_4\). These interactions are pivotal for explaining how the noble gas xenon participates in complex bonding scenarios.