Question

Sodium is heated in air at \(300^{\circ} \mathrm{C}\) to form \(\mathrm{X} . \mathrm{X}\) absorbs \(\mathrm{CO}_{2}\) and forms \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) and \(\mathrm{Y}\). Which of the following is \(\mathrm{Y} ?\) (a) \(\mathrm{O}_{2}\) (b) \(\mathrm{O}_{3}\) (c) \(\mathrm{H}_{2}\) (d) \(\mathrm{H}_{2} \mathrm{O}_{2}\)

Short answer

Y is O₂ (Option a).

Step-by-step solution

Identify the Reaction for X Formation

Sodium (\(\text{Na}\)) is heated in air at \(300^{\circ}\, \text{C}\) primarily reacts with oxygen to form sodium oxide, \(\text{Na}_2\text{O}\). The reaction can be written as: \[4\text{Na} + \text{O}_2 \rightarrow 2\text{Na}_2\text{O}\]So, in the first step, \(\mathrm{X} = \mathrm{Na}_2\mathrm{O}\).

Identify the Reaction of X with CO2

Given that \(\mathrm{X}\) (which is sodium oxide, \(\mathrm{Na}_2\mathrm{O}\)) absorbs \(\mathrm{CO}_2\), it forms sodium carbonate (\(\mathrm{Na}_2\mathrm{CO}_3\)). The reaction is:\[\text{Na}_2\text{O} + \text{CO}_2 \rightarrow \text{Na}_2\text{CO}_3\]This reaction does not initially indicate any by-products.

Consider the Options for Y

As per the problem, a by-product \(\mathrm{Y}\) is formed. Typically, the reaction between \(\mathrm{Na}_2\mathrm{O}\) and \(\mathrm{CO}_2\) doesn't produce a gaseous by-product, so \(\mathrm{Y}\) could either be directly formed from \(\mathrm{Na}_2\mathrm{O}\) with \(\mathrm{CO}_2\) or be an assumption based on the choices given.

Evaluate the Given Options

Among the given options (a) \(\mathrm{O}_{2}\), (b) \(\mathrm{O}_{3}\), (c) \(\mathrm{H}_{2}\), (d) \(\mathrm{H}_{2} \mathrm{O}_{2}\), based on typical reactions, oxygen (\(\mathrm{O}_2\)) is often observed as a gas released when a metal oxide absorbs \(\mathrm{CO}_2\), especially in simplified or hypothetical scenarios.

Conclude the Identity of Y

Based on typical problems of this nature and the likely assumption given the choices, \(\mathrm{Y}\) is most strongly considered as \(\mathrm{O}_{2}\) (option a).

Key concepts

Sodium

Sodium is a soft, silvery-white metal known for its high reactivity, particularly with oxygen. At normal conditions, sodium is stored under oil to prevent it from coming into contact with moisture and oxygen in the air. This is because sodium reacts vigorously with these elements, leading to the formation of sodium oxide. This reaction becomes even more pronounced at elevated temperatures.
When sodium is heated to around 300°C in the air, it reacts specifically with the oxygen component. The resulting product of this reaction is sodium oxide ( ext{Na}_2 ext{O}), as outlined in the chemical reaction:

• 4 ext{Na} + ext{O}_2 ightarrow 2 ext{Na}_2 ext{O}

Sodium oxide is an essential starting point for understanding how it further engages in chemical interactions, such as with carbon dioxide.

CO2 Absorption

The process of CO2 absorption refers to the chemical reaction where certain compounds or substances capture and integrate carbon dioxide into their structure. Sodium oxide is one such substance that can absorb ext{CO}_2. This is not only crucial for industrial processes but also as a fundamental laboratory reaction.
When sodium oxide ( ext{Na}_2 ext{O}) comes into contact with carbon dioxide ( ext{CO}_2), a compound conversion takes place, resulting in the formation of sodium carbonate ( ext{Na}_2 ext{CO}_3). The conversion can be represented with the equation:

• ext{Na}_2 ext{O} + ext{CO}_2 ightarrow ext{Na}_2 ext{CO}_3

In this scenario, the absorption of carbon dioxide by sodium oxide does not initially seem to produce any additional substances directly in the equation. However, the nature of chemistry sometimes involves products or by-products in unexpected forms.

Chemical By-products

In many chemical reactions, by-products can form alongside the main products. These by-products may not be directly apparent in the initial reaction equation but might still appear through various side processes or assumptions.
In the case of sodium oxide absorbing ext{CO}_2 to form sodium carbonate, there is a possibility of creating an additional substance, especially given the context of the problem. Among possible by-products, oxygen ( ext{O}_2) can be generated. This is due to the breakdown and recombination of elements during the reaction process.
In the given scenario, while the visible equation doesn’t suggest a by-product, practical chemistry sometimes involves identifying such components based on theoretical reaction pathways or specific conditions, such as simplifying assumptions in educational exercises.

Chemical Reaction Steps

Understanding chemical reaction steps is essential for solving problems related to chemical reactions. Breaking down each step helps in identifying the products and reactants involved. This approach also clarifies potential by-products.
The reaction starts with sodium heated in air:

• ext{4Na + O}_2 ightarrow ext{2Na}_2 ext{O}

Next, sodium oxide reacts with carbon dioxide:

• ext{Na}_2 ext{O} + ext{CO}_2 ightarrow ext{Na}_2 ext{CO}_3

Finally, the exercise requires identifying any additional by-product 'Y'. In educational problems, assumptions based on provided options are often necessary. Typical assumptions might lead to concluding that oxygen ( ext{O}_2) is the by-product in this scenario.
This structured approach emphasizes the importance of logical deduction in chemistry, allowing learners to consider practical possibilities alongside theoretical knowledge.