Problem 89 - A Complete Resource Book in Chemistry for JEE Main

Question

Which of the following is the strongest oxidizing agent? (a) \(\mathrm{F}_{2}\) (b) \(\mathrm{Cl}_{2}\) (c) \(\mathrm{Br}_{2}\) (d) \(\mathrm{I}_{2}\)

Step-by-Step Solution

Answer

The strongest oxidizing agent is \\( \text{F}_2 \\).

Step 1: Identify the Concept

An oxidizing agent is a substance that has the ability to oxidize other substances, meaning it can accept electrons from them during a chemical reaction. Thus, the strongest oxidizing agent is the one that has the highest tendency to gain electrons.

Step 2: Refer to the Halogen Group

The elements listed are halogens: \( ext{F}_2, ext{Cl}_2, ext{Br}_2, ext{and I}_2 \) . In the periodic table, halogens are known to be strong oxidizing agents, and their ability to gain electrons as oxidizing agents decreases down the group.

Step 3: Determine the Trend

In the periodic table, as you move down the halogen group, from fluorine to iodine, the electronegativity and strength of oxidizing agents decrease. This means that \( ext{F}_2 \) is the strongest oxidizing agent among the halogens.

Step 4: Conclusion

Based on the trend, \( ext{F}_2 \) has the highest tendency to gain electrons compared to the other halogens listed. Therefore, it is the strongest oxidizing agent among the given options.

Key Concepts

Halogens in Periodic Table

The periodic table is a way to arrange chemical elements based on their properties. One of the main groups we've focused on here is the halogens. These elements reside in Group 17, known for their high reactivity.
Halogens include fluorine ( abla_{F} ), chlorine ( abla_{Cl} ), bromine ( abla_{Br} ), and iodine ( abla_{I} ).
These elements are non-metals and have seven electrons in their outer shell. With just one electron missing to reach a stable octet configuration, they have a strong desire to gain that final electron. This makes them excellent oxidizing agents.

• Fluorine is at the top of the group and is the most reactive.
• Iodine is at the bottom and is the least reactive of the four.

The reactivity of halogens is due to their electron configurations and their high electronegativity values.

Electronegativity Trend

Electronegativity measures how strongly an atom can attract or hold onto electrons in a bond.
This property plays a crucial role in determining the strength of oxidizing agents among halogens.
In the periodic table, electronegativity increases as you move from left to right across a period. However, it decreases as you move down a group.

• Fluorine, being at the top of Group 17, has the highest electronegativity.
• Iodine, positioned lower, has a significantly lower electronegativity.

Because of its high electronegativity, fluorine is extremely effective at pulling electrons towards itself.
Hence, it acts as the strongest oxidizing agent compared to its fellow halogens.

Chemical Reactions

A chemical reaction involves the transformation of reactants into products. Oxidizing and reducing agents play pivotal roles in these processes. Oxidizing agents undergo a reduction by gaining electrons, hence assisting in the oxidation of other substances.
When halogens participate in reactions, they typically gain electrons from other species, thereby driving the oxidation process.

• In reactions with metals, halogens like fluorine and chlorine are likely to completely strip electrons from the metal.
• This results in the formation of metal halides, where the halogen has gained electrons.

The ability of a halogen to act as an oxidizing agent is linked to its position in the periodic table, with higher position halogens like fluorine showing the strongest oxidizing properties.

Electron Gain Tendency

The tendency to gain electrons is crucial in determining how strongly an element acts as an oxidizing agent. For halogens, gaining an electron fulfills their desire to achieve a stable electron configuration. This makes them particularly keen electron acceptors.
Each halogen is only one electron short of a noble gas configuration, giving them a significant drive to gain an electron.

• Fluorine, at the very top, has the greatest electron gain tendency due to its high electronegativity and small atomic size.
• Iodine, being larger and having lower electronegativity, has a far lesser tendency to gain electrons.

Because of these properties, fluorine is the most powerful oxidizing agent within the halogen group, efficiently accepting electrons in chemical reactions.