Question

69\. The sum of the oxidation states of the atoms in a polyatomic ion is equal to the overall ____ of the ion.

Short answer

The sum of the oxidation states of the atoms in a polyatomic ion is equal to the overall \(\underline{charge}\) of the ion.

Step-by-step solution

Understand the Concept of Oxidation States and Polyatomic Ions

An oxidation state is a number assigned to an atom in a molecule or ion that represents its "electron ownership" in a chemical bond. It helps to determine how electrons are shared or transferred among atoms during a chemical reaction. A polyatomic ion is a group of two or more atoms covalently bonded together that carry an overall electric charge. The sum of the oxidation states of the atoms in a polyatomic ion should equal its overall electric charge.

Fill in the Missing Word

Now that we understand the relationship between the oxidation states and the overall charge of a polyatomic ion, we can complete the sentence using this understanding. 69. The sum of the oxidation states of the atoms in a polyatomic ion is equal to the overall \(\underline{charge}\) of the ion. The missing word in the sentence is "charge."

Key concepts

Understanding Chemical Bonding

Diving into the intricate world of atoms and molecules, chemical bonding is the force that ties atoms together, forming more complex structures. The types of bonds are covalent, ionic, and metallic. Covalent bonds involve the sharing of electron pairs between atoms. In contrast, ionic bonds arise from the electrical attraction between charged particles or ions, where an electron is transferred from one atom to another.

In polyatomic ions, the atoms are held together by covalent bonds, yet the entity carries a net charge due to the loss or gain of electrons. This charge impacts the ion's behavior in reactions and its interaction with other charged species. Understanding these basic principles of bonding lays the foundation for grasping more intricate chemical phenomena.

Deciphering Polyatomic Ion Charge

A polyatomic ion is akin to a tightly-knit squad where each atom contributes to the team's overall electric charge. The charge of a polyatomic ion is the sum of the oxidation states of each atom within it. Simply put, it's the algebraic sum of the 'electron ownership' of all the atoms—dictating how many electrons the ion has gained or lost compared to its neutral state.

For instance, the sulphate ion (SO_4^{2-}) has a total charge of -2, implying that overall, it has acquired two extra electrons. Delving into the oxidation states of its atoms, one finds that sulphur has an oxidation state of +6 while each oxygen has -2, resulting in the sum (+6) + 4(-2) = -2, echoing the ion's charge. This charge is a crucial factor in understanding the polyatomic ion's reactivity and how it bonds with other ions in chemical reactions.

Electron Transfer in Chemical Reactions

Electrons are the unsung heroes of chemical reactions, orchestrating every transformation. Electron transfer between atoms and molecules is at the heart of many reactions. When an atom loses an electron, it is oxidized, while gain of an electron leads to reduction—truly, a dance of electrons.

This transfer determines the chemical properties and reactivity of the elements involved. In oxidation-reduction (redox) reactions, the total number of electrons lost is equal to the total number gained, ensuring charge conservation. Such electron exchanges are not limited to simple ions but occur in polyatomic ions and their bonding as well, influencing the overall charge and stability of the products formed.