Question

Write equations representing the following processes: (a) The electron affinity of $S^{-}$ (b) The third ionization energy of titanium (c) The electron affinity of ${\mathrm{Mg}}^{2+}$ (d) The ionization energy of ${\mathrm{O}}^{2-}$

Short answer

(a) $S^{-}+e^{-}\to S^{2-}$; (b) ${\text{Ti}}^{2+}\to {\text{Ti}}^{3+}+e^{-}$; (c) ${\text{Mg}}^{2+}+e^{-}\to {\text{Mg}}^{+}$; (d) ${\mathrm{O}}^{2-}\to {\mathrm{O}}^{-}+e^{-}$.

Step-by-step solution

Understanding Electron Affinity

The electron affinity is the energy change that occurs when an electron is added to an atom or ion. For sulfur anion $S^{-}$, we want to write the equation where it gains an additional electron.

Electron Affinity of S-

The process where $S^{-}$ gains an electron is represented by: $$S^{-}+e^{-}\to S^{2-}$$

Understanding Ionization Energy

Ionization energy is the amount of energy required to remove an electron from an atom or ion. For the third ionization energy of titanium $\text{Ti}$, it means removing the third electron in sequence after the first two.

Third Ionization Energy of Titanium

The equation for the third ionization energy of titanium is: $${\text{Ti}}^{2+}\to {\text{Ti}}^{3+}+e^{-}$$

Electron Affinity of Mg2+

Similar to sulfur but now ${\text{Mg}}^{2+}$ gains an electron. The process is described by the following chemical equation.

Electron Affinity of Mg2+

The equation for ${\text{Mg}}^{2+}$ gaining an electron is: $${\text{Mg}}^{2+}+e^{-}\to {\text{Mg}}^{+}$$

Ionization Energy of O2-

For ${\mathrm{O}}^{2-}$, the ionization energy refers to the energy needed to remove an electron from the ionized oxygen.

Ionization Energy of O2-

The equation for the ionization of ${\mathrm{O}}^{2-}$ is: $${\mathrm{O}}^{2-}\to {\mathrm{O}}^{-}+e^{-}$$

Key concepts

Ionization Energy

Ionization energy is a fundamental concept in chemistry. It describes the energy required to remove an electron from a neutral atom or ion. This energy is typically measured in kilojoules per mole (kJ/mol).

• The process of ionization involves increasing energy levels as electrons are removed sequentially.
• Once an electron is removed, the ion becomes positively charged due to the imbalance of protons and electrons.
• The first ionization energy refers to removing the first electron, the second to the second electron, and so on.

Ionization energy can tell us a lot about the reactivity and stability of elements. For instance, elements with low ionization energies tend to lose electrons easily, making them reactive.

Sulfur Anion

A sulfur anion is an ion form of sulfur, denoted as $S^{-}$. The creation of anions involves the addition of electrons to neutral atoms. As more electrons are added, the atom becomes negatively charged due to the surplus of electrons relative to protons. When we talk about the electron affinity of a sulfur anion, we mean the energy change when an additional electron is added. The reaction can be represented as:$$S^{-}+e^{-}\to S^{2-}$$

• This process involves gaining a second electron, making the sulfur more negatively charged.
• Understanding this concept helps in predicting the formation and stability of molecules in chemical reactions.

Titanium Ionization

Titanium ionization involves stepwise removal of electrons from titanium. The third ionization energy, specifically, refers to the energy required to remove the third electron from a titanium ion.

• Consider a neutral titanium ($\text{Ti}$) atom losing three electrons to become ${\text{Ti}}^{3+}$.
• Each subsequent electron removal requires more energy due to stronger attraction between the electrons and the nucleus.

The chemical equation for the third ionization energy is:$${\text{Ti}}^{2+}\to {\text{Ti}}^{3+}+e^{-}$$Understanding the ionization process of titanium is crucial, especially in areas like materials science and engineering, where titanium alloys are widely used for their strength and corrosion resistance.

Magnesium Cation

The magnesium cation $({\text{Mg}}^{2+})$ plays an important role in chemistry and biochemistry. Cations are formed when electrons are removed from atoms, leading to a net positive charge. In magnesium, the electron affinity represents the energy change as an electron is added to the cation:$${\text{Mg}}^{2+}+e^{-}\to {\text{Mg}}^{+}$$

• This conversion describes the initial step towards reducing magnesium from a doubly positive charged ion to a singly positive charged ion.
• Such transformations are often related to metabolic processes or industrial procedures involving magnesium.

By understanding cations, we gain insights into bonding, reactivity, and the various applications of magnesium across different fields.