|
Correct Answer: 1
0.5 to determine the bond order of the peroxide ion (o2^2-), we need to understand the concept of bond order and how it is calculated using molecular orbital theory (mot). bond order is a measure of the strength and stability of a bond, calculated as half the difference between the number of bonding electrons (nb) and anti-bonding electrons (na) in a molecule.
1 in the case of o2^2-, we start by considering the electron configuration of the neutral oxygen molecule (o2), which has a total of 16 electrons. according to molecular orbital theory, these electrons fill the molecular orbitals from the lowest to the highest energy levels. the order of filling for o2, based on mot, is σ(2s)^2, σ*(2s)^2, π(2p)^4, σ(2p)^2, π*(2p)^2.
1.5 when two additional electrons are added to form o2^2-, they occupy the next available anti-bonding molecular orbitals. since the π*(2p) orbitals are partially filled with two electrons in the neutral o2, the addition of two more electrons completely fills these π*(2p) orbitals. this results in the electronic configuration: σ(2s)^2, σ*(2s)^2, π(2p)^4, σ(2p)^2, π*(2p)^4.
2 to find the bond order, we calculate the difference between the number of electrons in bonding orbitals and those in anti-bonding orbitals and then divide by two. for o2^2-, the bonding orbitals (σ(2s), π(2p), and σ(2p)) contain a total of 8 electrons (2 in σ(2s), 4 in π(2p), and 2 in σ(2p)), and the anti-bonding orbitals (σ*(2s) and π*(2p)) also contain a total of 8 electrons (2 in σ*(2s) and 6 in π*(2p)). the bond order is then calculated as (8 - 8) / 2 = 0.
2 therefore, the bond order of o2^2- is 0, indicating that there are no net bonding interactions in this ion, which explains its relatively unstable and reactive nature. this is consistent with the fact that peroxide ions are often found in ionic states, stabilizing through interactions with cations rather than existing as diatomic molecules.
|
