Question

Which of the following Can beoxidized by \(\mathrm{O}_{3}\) ? (a) KI (b) \(\mathrm{FeSO}_{4}\) (c) \(\mathrm{KMnO}_{4}\) (d) \(\mathrm{K}_{2} \mathrm{MnO}_{4}\)

Short answer

KI and FeSO_4 can be oxidized by ozone (O_3).

Step-by-step solution

Understanding Oxidation

Oxidation involves the loss of electrons by a substance. Therefore, we need to identify which substances among the options can lose electrons to ozone (O}_3) as it acts as an oxidizing agent.

Analyzing Each Option

Examine each option to see if they can give up electrons to ozone: - **KI (Potassium Iodide):** Iodide ions (I^-), can be oxidized to iodine (I_2) by ozone. - **FeSO_4 (Ferrous Sulfate):** The ferrous ion (Fe^{2+}) can be oxidized to the ferric ion (Fe^{3+}) by ozone. - **KMnO_4 (Potassium Permanganate):** This is already in the highest oxidation state of manganese and cannot be further oxidized. - **K_2MnO_4 (Potassium Manganate):** It cannot be oxidized further by O_3 as manganese is already in a high oxidation state.

Identify the Oxidizable Substances

Based on the analysis, the substances that can be oxidized by ozone are KI and FeSO_4, as they can undergo oxidation from lower to higher oxidation states.

Key concepts

Oxidation State

The oxidation state, also known as the oxidation number, is an indicator of the degree of oxidation of an atom in a chemical substance. It helps to describe electron distribution within molecules.

In layman's terms, think of the oxidation state as a kind of "account balance" for electrons. When an atom loses or gains electrons, the balance shifts. Higher oxidation numbers mean the atom has lost more electrons, while lower numbers mean it has gained electrons or lost fewer.

• For instance, in O_3 (ozone), each oxygen has an oxidation state of 0 because O_3 consists of elemental oxygen.
• In compounds like Fe^{2+} in ferrous sulfate ( FeSO_4), iron has an oxidation state of +2, indicating it has lost two electrons.

Understanding oxidation states is crucial in identifying how elements interact during chemical reactions and determining their ability to undergo oxidation or reduction.

Oxidizing Agents

Oxidizing agents are substances that promote oxidation by accepting electrons from other substances. This means they help other substances to lose electrons, undergoing reduction in the process.

Ozone ( O_3) is a powerful oxidizing agent because it can readily accept electrons.

• When KI reacts with O_3, iodide ions ( I^-) are oxidized to iodine ( I_2) because O_3 takes their electrons.
• Similarly, ferrous ions ( Fe^{2+}) in FeSO_4 are converted to ferric ions ( Fe^{3+}) when oxidized by ozone.

In this context, ozone acts as the electron acceptor, causing the species it interacts with to lose electrons and thus be oxidized.

Electron Loss

Electron loss is a core feature of oxidation reactions. When a substance loses electrons, it is being oxidized. This is a central concept in redox chemistry.

Consider what happens when iron in ferrous sulfate ( FeSO_4) loses an electron. The iron ion changes from Fe^{2+} to Fe^{3+}, indicating oxidation. Similarly, when iodide ions ( I^-) lose electrons, they form iodine ( I_2).

• Each electron lost in these reactions was initially bound to the atom, contributing to its properties.
• By losing an electron, the atom's charge increases, altering its oxidation state.

The ability to undergo electron loss is why some substances are more susceptible to being oxidized by strong oxidizing agents like ozone.

Oxidation of Compounds

Oxidation of compounds involves changing the oxidation state of elements within them by losing electrons. Whether a compound can be oxidized depends on the current oxidation states of its constituent elements.

For example, KMnO_4 and K_2MnO_4 contain manganese in high oxidation states, meaning these compounds are less likely to undergo further oxidation.

• KMnO_4 has manganese in an oxidation state of +7, which is already very high and indicates its inability to donate more electrons.
• In contrast, KI and FeSO_4 have constituents with electron configurations that allow further oxidation when they interact with an oxidizing agent like ozone.

Understanding which compounds can be oxidized is essential for predicting and controlling chemical reactions in various applications.