Iodine pentoxide, \(\mathrm{I}_{2} \mathrm{O}_{5}\), is sometimes used to remove carbon monoxide from the air by forming carbon dioxide and iodine. Write a balanced equation for this reaction and identify species that are oxidized and reduced.

Oxidation-reduction reactions, commonly known as redox reactions, involve the transfer of electrons between two substances. They are a vital part of many chemical processes, both biological and industrial. An easy way to remember what happens in a redox reaction is to use the mnemonic OIL RIG, which stands for 'Oxidation Is Loss, Reduction Is Gain' of electrons.

In our textbook problem, we identify the redox reaction where carbon monoxide (CO) reacts with iodine pentoxide (\(I_2O_5\)) to form carbon dioxide (CO2) and iodine (I2). Carbon monoxide is oxidized as it loses electrons when it is converted to carbon dioxide. On the other hand, iodine pentoxide is reduced, as it gains electrons when the iodine's chemical form changes from being part of iodine pentoxide to elemental iodine.

The importance of redox reactions goes beyond just balancing chemical equations. These reactions are central to processes such as combustion, corrosion, and photosynthesis, making them fundamental to a wide array of scientific fields.

The concept of chemical stoichiometry is the calculation of the quantities of reactants and products in chemical reactions. It's based on the law of conservation of mass, which states that mass is neither created nor destroyed in a chemical reaction. Therefore, the mass of the reactants must equal the mass of the products. When we balance a chemical equation, like the reaction between iodine pentoxide and carbon monoxide, we are essentially applying stoichiometric principles to ensure that the number of atoms for each element is the same on both sides of the equation.

For example, in our balanced equation \(I_2O_5 + 5CO \rightarrow 5CO_2 + I_2\), the coefficients indicate the stoichiometric ratios. It shows that one molecule of iodine pentoxide reacts with five molecules of carbon monoxide to produce five molecules of carbon dioxide and one molecule of iodine. Understanding stoichiometry can also aid in predicting how much reactant is needed to create a desired amount of product, which is incredibly important in industrial applications like pharmaceuticals production and material synthesis.

The concept of oxidation states, or oxidation numbers, serves as a bookkeeping tool in chemistry to keep track of the transfer of electrons in redox reactions. Oxidation states indicate the formal charge of an atom if all bonds were considered to be ionic, despite the actual bond type. They are assigned by a set of rules, such as the fact that the oxidation state of an atom in a pure element is 0, and for a molecule, the sum of the oxidation states is equal to the charge of the molecule.

In the reaction at hand, the oxidation state of carbon in CO is +2, and it increases to +4 in CO2, indicating oxidation. The iodine in \(I_2O_5\) has an oxidation state of +5, and in I2, the oxidation state is 0, indicating reduction. By analyzing these oxidation states, students are equipped to identify which species are oxidized and which are reduced in a chemical reaction. This understanding is fundamental for mastering redox reactions and for various real-life applications, including energy storage in batteries and the prevention of metal corrosion.