Problem 163 - A Complete Resource Book in Chemistry for JEE Main

Question

\(\mathrm{KO}_{2}\) (potassium super oxide) is used in oxygen cylinders in space and submarines because it (a) produces ozone (b) absorbs \(\mathrm{CO}_{2}\) (c) absorbs \(\mathrm{CO}_{2}\) and increase \(\mathrm{O}_{2}\) contents (d) eliminates moisture

Step-by-Step Solution

Answer

KO2 absorbs CO2 and increases O2 content, making (c) the correct choice.

Step 1: Analyze the Composition of KO2

Potassium superoxide, or \( \text{KO}_2 \), is a strong oxidizer that reacts readily with carbon dioxide and moisture in the air. We need to consider what happens when it reacts with these substances to understand its use.

Step 2: Reaction with Carbon Dioxide

The chemical reaction of \( \text{KO}_2 \) with carbon dioxide is given by the equation: \( 4\text{KO}_2 + 2\text{CO}_2 \rightarrow 2\text{K}_2\text{CO}_3 + 3\text{O}_2 \). This shows that \( \text{KO}_2 \) absorbs \( \text{CO}_2 \) and produces \( \text{O}_2 \).

Step 3: Evaluate the Options Provided

Consider each option: (a) \( \text{KO}_2 \) does not produce ozone; (b) it absorbs \( \text{CO}_2 \); (c) it absorbs \( \text{CO}_2 \) and increases \( \text{O}_2 \) content; (d) it does not specifically eliminate moisture. The reaction aligns exactly with option (c).

Step 4: Conclusion

From the analysis and specific reaction of \( \text{KO}_2 \) with \( \text{CO}_2 \), the correct answer is option (c) which describes that \( \text{KO}_2 \) absorbs \( \text{CO}_2 \) and increases \( \text{O}_2 \) content.

Key Concepts

Reaction with Carbon Dioxide

Potassium superoxide, represented as \( \text{KO}_2 \), is known for its unique reaction with carbon dioxide (\( \text{CO}_2 \)). This occurs because \( \text{KO}_2 \) is a strong oxidizing agent that can efficiently interact with \( \text{CO}_2 \), resulting in a chemical transformation.
The reaction between potassium superoxide and carbon dioxide can be represented with the chemical equation:

• \[ 4\text{KO}_2 + 2\text{CO}_2 \rightarrow 2\text{K}_2\text{CO}_3 + 3\text{O}_2 \]

This equation tells us that four units of \( \text{KO}_2 \) react with two units of \( \text{CO}_2 \) to form two units of potassium carbonate (\( \text{K}_2\text{CO}_3 \)) and three units of oxygen gas (\( \text{O}_2 \)). The importance of this reaction lies in its role in both capturing carbon dioxide and generating oxygen, which is crucial for life-supporting environments like submarines and spacecraft.
By facilitating this dual action, \( \text{KO}_2 \) becomes an essential component in closed systems where maintaining breathable air is vital.

Oxygen Generation

A significant characteristic of potassium superoxide is its ability to produce oxygen when reacting with carbon dioxide. This is particularly beneficial in enclosed environments. Let's see how the process unfolds.
During its reaction with \( \text{CO}_2 \), \( \text{KO}_2 \) undergoes a transformation that is not only absorbing the carbon dioxide but is simultaneously releasing oxygen.

• This newly liberated oxygen (\( \text{O}_2 \) ) then mixes with the surrounding air, increasing the available oxygen content.

This capability is especially valuable in specialized scenarios like space missions or underwater excursions, where oxygen supplies are limited and atmospheric control is paramount.
The main advantage here is that as \( \text{KO}_2 \) continues to absorb \( \text{CO}_2 \), it keeps producing oxygen, ensuring a continuous source of breathable air. This process is self-sustaining as long as there is sufficient \( \text{CO}_2 \), making it a clever solution for managing life-support systems.

CO2 Absorption

The absorption of carbon dioxide is another crucial property of potassium superoxide. This process is instrumental in maintaining a clean and breathable atmosphere in sealed environments.
As \( \text{KO}_2 \) reacts with \( \text{CO}_2 \), it forms potassium carbonate, \( \text{K}_2\text{CO}_3 \). Specifically, during this reaction:

• The \( \text{CO}_2 \) is captured, effectively reducing its concentration in the environment.
• Potassium carbonate is created as a byproduct.

Lowering the levels of carbon dioxide is essential in preventing the buildup of this gas, which can be harmful in high concentrations.
This absorption capability helps maintain the air quality in places where traditional ventilation might not be possible. It's a convenient method for removing exhaled \( \text{CO}_2 \) and making sure the environment remains safe for continuous human presence. Thus, \( \text{KO}_2 \), through its dual action of absorbing \( \text{CO}_2 \) and generating \( \text{O}_2 \), plays a fundamental role in life-support systems.