Question

The correct order of electronegativity for \(\mathrm{O}, \mathrm{O}^{+}\) and \(\mathrm{O}^{--}\) is: (a) \(\mathrm{O}^{-}>\mathrm{O}>\mathrm{O}^{+}\) (b) \(\mathrm{O}>\mathrm{O}^{+}>\mathrm{O}^{-}\) (c) \(\mathrm{O}^{+}>\mathrm{O}^{-}>\mathrm{O}\) (d) \(\mathrm{O}^{+}>\mathrm{O}>\mathrm{O}^{-}\)

Short answer

(d) \(\mathrm{O}^{+} > \mathrm{O} > \mathrm{O}^{-}\)

Step-by-step solution

Understand Electronegativity

Electronegativity is the tendency of an atom to attract electrons in a chemical bond. It depends on the charge and the distance of valence electrons from the nucleus.

Analyze Oxygen Species Charges

Consider the charges on the species: \(\mathrm{O}^{+}\) has a positive charge, \(\mathrm{O}\) is neutral, and \(\mathrm{O}^{-}\) has a negative charge. A higher positive charge suggests a greater ability to attract electrons due to increased nuclear attraction.

Rank Based on Electronegativity

Given the charges, \(\mathrm{O}^{+}\) should have the highest electronegativity because the positive charge increases its ability to attract electrons. Neutral \(\mathrm{O}\) would have a medium value, and \(\mathrm{O}^{-}\) would have the lowest electronegativity due to electron-electron repulsion in the added electron.

Identify Correct Answer Choice

Based on the analysis, the order of electronegativity is \(\mathrm{O}^{+} > \mathrm{O} > \mathrm{O}^{-}\). Therefore, the correct answer is option (d).

Key concepts

Understanding Oxygen Species

Oxygen species refer to the different forms an oxygen atom can take when it gains or loses electrons. In this specific scenario, we are looking at three species:

• Oxygen with a positive charge, noted as \(\mathrm{O}^{+}\).
• Neutral oxygen, simply written as \(\mathrm{O}\).
• Oxygen with a negative charge, known as \(\mathrm{O}^{-}\).

These variations occur when oxygen loses or gains electrons, affecting its properties such as electronegativity.
The positively charged oxygen species, \(\mathrm{O}^{+}\), has one less electron than neutral oxygen, resulting in a strong positive nuclear attraction. The excess positive charge can pull in electrons from surrounding atoms more effectively. Neutral oxygen, \(\mathrm{O}\), has the number of electrons balanced with its protons, giving it moderate electron-attracting ability. Lastly, the negatively charged \(\mathrm{O}^{-}\) has an extra electron, which introduces electron-electron repulsion making it less effective at attracting additional electrons.
Understanding these species helps explain differences in how oxygen atoms behave when participating in chemical reactions.

Chemical Bonding and Electronegativity

Chemical bonding occurs when atoms interact and share or transfer electrons. The concept of electronegativity plays a crucial role in determining the nature of these bonds. Electronegativity is essentially how strongly an atom attracts electrons during bonding.
It is crucial to note here that electronegativity differences influence whether a bond is more ionic or covalent. A higher electronegative atom attracts electrons more forcefully, which can lead to polar covalent bonds where electrons are unevenly shared.
In the context of the oxygen species in the exercise, the order of electronegativity—\(\mathrm{O}^{+} > \mathrm{O} > \mathrm{O}^{-}\)—directly impacts how these oxygen species would participate in chemical bonds.

• \(\mathrm{O}^{+}\) exhibits the highest electronegativity, indicating it is likely to attract electrons most effectively, making it a stronger participant in forming polar covalent bonds.
• \(\mathrm{O}\) has a balanced electronegativity, leading to typical oxygen behaviors in forming covalent bonds.
• \(\mathrm{O}^{-}\) has the lowest electronegativity, which might make it less likely to attract additional electrons effectively, particularly against more electronegative elements. Instead, it may act more like an electron donor in certain chemical environments.

Atomic Charge Effect on Electronegativity

The atomic charge significantly influences an atom's electronegativity. A positive charge, as seen in \(\mathrm{O}^{+}\), results from the loss of an electron, which causes the remaining electrons to be held more tightly by the nucleus. This stronger grip increases the atom's electronegativity since the positively charged nucleus attracts electrons more effectively.
Conversely, a negative charge, as present in \(\mathrm{O}^{-}\), arises from the gain of an electron, which leads to increased electron-electron repulsion. This repulsion slightly counteracts the nuclear pull, reducing the atom's ability to attract additional electrons, and thus decreases its electronegativity.
Neutral oxygen, \(\mathrm{O}\), reflects a balance between protons and electrons, providing a moderate level of electronegativity. As a result, changes in atomic charge radically alter the electronegativity of an atom and, consequently, its chemical behavior and reactivity. Understanding how atomic charge affects electronegativity accentuates the importance of these interactions in chemical bonding.
These concepts not only help in understanding the immediate exercises in textbooks but also provide foundational knowledge useful for delving into more complex chemical studies.