Question

Chlorine behaves as an oxidizing agent upon reaction with (a) \(\mathrm{Na}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}\) (b) \(\mathrm{NaNO}_{2}\) (c) \(\mathrm{Fe}_{2}\left(\mathrm{SO}_{4}\right)_{3}\) (d) \(\mathrm{O}_{3}\)

Short answer

(a) Na2S2O3 and (b) NaNO2 react as oxidizing agents with chlorine.

Step-by-step solution

Identify Redox Reaction

An oxidizing agent is a substance that accepts electrons in a redox reaction. It is reduced while oxidizing another substance. We'll need to find a reaction where chlorine gains electrons (is reduced), which means that the other substance must be oxidized.

Analyze Reaction with Na2S2O3

Analyze the reaction of chlorine with \(\mathrm{Na}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}\). Chlorine (\(Cl_2\)) oxidizes the thiosulfate ion \(\mathrm{S}_{2} \mathrm{O}_{3}^{2-}\) to tetrathionate ion \(\mathrm{S}_{4} \mathrm{O}_{6}^{2-}\) while chlorine is reduced to chloride ions (\(\mathrm{Cl}^-\)). This is a redox reaction.

Evaluate Reaction with NaNO2

Consider the reaction of \(Cl_2\) with \(\mathrm{NaNO}_{2}\). Chlorine oxidizes nitrite ions \(\mathrm{NO}_2^-\) to nitrate ions \(\mathrm{NO}_3^-\), while it itself is reduced to chloride ions \(\mathrm{Cl}^-\). This is another redox reaction.

Examine Reaction with Fe2(SO4)3

Examine the potential reaction of \(Cl_2\) with \(\mathrm{Fe}_{2}\left(\mathrm{SO}_{4}\right)_{3}\). Since \(\mathrm{Fe}_{2}\left(\mathrm{SO}_{4}\right)_{3}\) contains \(\mathrm{Fe}^{3+}\), which is already in an oxidized state, chlorine does not further oxidize it. No electron transfer occurs, therefore no redox reaction takes place.

Investigate Reaction with O3

Investigate the interaction between \(Cl_2\) and ozone (\(O_3\)). Ozone is a powerful oxidizing agent itself, and typically, such similar strong oxidizers do not result in a redox reaction. Chlorine does not oxidize in this context.

Key concepts

Oxidizing Agents

In chemistry, oxidizing agents play a crucial role in redox reactions. These agents are substances that accept electrons during a reaction. By gaining electrons, they themselves are reduced. This might seem counterintuitive, since the oxidizing agent causes another substance to lose electrons, or be oxidized.
Understanding the nature of oxidizing agents is essential to grasp how redox reactions function overall and how substances like chlorine can transform during these processes.

• Oxidizing agents are integral to redox reactions, facilitating the oxidation of other substances.
• Their main role is to gain electrons, which makes them reduced in the process.
• An understanding of oxidizing agents helps predict and balance chemical equations.

For instance, in the reaction between chlorine and sodium thiosulfate (\(\mathrm{Na}_{2} \mathrm{S}_{2} \mathrm{O}_{3}\)) or sodium nitrite (\(\mathrm{NaNO}_{2}\)), chlorine acts as an oxidizing agent, accepting electrons and thus being reduced to chloride ions (\(\mathrm{Cl}^-\)).

Electron Transfer

Electron transfer is the hallmark of redox reactions, involving the movement of electrons from one substance to another. This transfer is what defines the oxidation and reduction processes.
In any given redox reaction, the substance that loses electrons becomes oxidized, while the one that gains electrons becomes reduced. This electron juggling is key to driving many chemical reactions.

• Electron transfer dictates the direction and outcome of redox reactions.
• During electron transfer, oxidation occurs when electrons are lost, while reduction occurs when electrons are gained.
• This process is fundamental to the energy transfer mechanisms in chemistry.

Consider the case when chlorine reacts with sodium nitrite. Chlorine atoms gain electrons, demonstrating reduction, while nitrite ions lose electrons, showing oxidation. Understanding these processes can enhance your comprehension of redox mechanics.

Oxidation States

Oxidation states, or oxidation numbers, are crucial for keeping track of electrons in chemical reactions. They indicate the degree of oxidation or reduction of an atom within a compound.
By assigning oxidation states, chemists can determine how electrons are transferred in a redox reaction.

• Oxidation states help in predicting the products of a chemical reaction.
• They are essential in identifying which atoms undergo oxidation and reduction.
• Using oxidation states can simplify the balancing of redox equations.

For example, when chlorine interacts with sodium thiosulfate, we see changes in oxidation states, where chlorine goes from elemental chlorine (\(0\)) to chloride ions (\(-1\)). Thiosulfate ions, meanwhile, move to higher oxidation states, forming tetrathionate. Observing these changes helps detail the complex choreography of electron movement in reactions.