Question

Write balanced equations for reactions between (a) \(\mathrm{Na}_{2} \mathrm{O}_{2}\) and water (b) \(\mathrm{KO}_{2}\) and water (c) \(\mathrm{Na}_{2} \mathrm{O}\) and \(\mathrm{CO}_{2}\).

Short answer

(a) \( 2\mathrm{Na}_2\mathrm{O}_2 + 2\mathrm{H}_2\mathrm{O} \rightarrow 4\mathrm{NaOH} + \mathrm{O}_2 \); (b) \( 4\mathrm{KO}_2 + 2\mathrm{H}_2\mathrm{O} \rightarrow 4\mathrm{KOH} + 3\mathrm{O}_2 + \mathrm{H}_2\mathrm{O}_2 \); (c) \( \mathrm{Na}_2\mathrm{O} + \mathrm{CO}_2 \rightarrow \mathrm{Na}_2\mathrm{CO}_3 \).

Step-by-step solution

Write the Reactants and Products for Reaction (a)

For the reaction between sodium peroxide (\( \mathrm{Na}_2 \mathrm{O}_2 \)) and water (\( \mathrm{H}_2 \mathrm{O} \)), the products formed are sodium hydroxide (\( \mathrm{NaOH} \)) and oxygen gas (\( \mathrm{O}_2 \)).

Balance the Equation for Reaction (a)

Start by balancing the elements. The balanced equation is:\[ \mathrm{2Na}_2 \mathrm{O}_2 + 2 \mathrm{H}_2 \mathrm{O} \rightarrow 4 \mathrm{NaOH} + \mathrm{O}_2} \] This equation is balanced as the number of each type of atoms on both sides of the equation are equal.

Write the Reactants and Products for Reaction (b)

For the reaction between potassium superoxide (\( \mathrm{KO}_2 \)) and water (\( \mathrm{H}_2 \mathrm{O} \)), the products are potassium hydroxide (\( \mathrm{KOH} \)), oxygen gas (\( \mathrm{O}_2 \)), and hydrogen peroxide (\( \mathrm{H}_2 \mathrm{O}_2 \)).

Balance the Equation for Reaction (b)

Balance the elements involved to get:\[ 4 \mathrm{KO}_2 + 2 \mathrm{H}_2 \mathrm{O} \rightarrow 4 \mathrm{KOH} + 3 \mathrm{O}_2 + \mathrm{H}_2 \mathrm{O}_2 \] This equation is balanced regarding both atoms and charges.

Write the Reactants and Products for Reaction (c)

For the reaction between sodium oxide (\( \mathrm{Na}_2 \mathrm{O} \)) and carbon dioxide (\( \mathrm{CO}_2 \)), the product is sodium carbonate (\( \mathrm{Na}_2 \mathrm{CO}_3 \)).

Balance the Equation for Reaction (c)

The balanced equation becomes straightforward as it already respects atom balance:\[ \mathrm{Na}_2 \mathrm{O} + \mathrm{CO}_2 \rightarrow \mathrm{Na}_2 \mathrm{CO}_3 \] All atoms on each side match perfectly.

Key concepts

Balanced Equations

Chemical reactions often involve a transformation where the reactants turn into products. It's crucial to have balanced equations to uphold the law of conservation of mass. This law states that matter cannot be created or destroyed. Therefore, in any chemical equation, the number of each type of atom must be the same on both sides of the equation. When balancing equations, here are a few steps you can follow:

• List each element that appears in the equation.
• Count the number of atoms of each element in both the reactants and products.
• Add coefficients to balance the number of atoms for each element on both sides of the equation.
• Double-check to ensure that all elements are balanced and that the smallest possible coefficients are used.

Balanced equations are crucial for predicting the quantities of products formed and for understanding the stoichiometry of reactions.

Reaction Products

Understanding the products of a reaction helps in predicting the behavior of a chemical process. You've seen examples of reactions involving different metal oxides in the exercises: sodium peroxide, potassium superoxide, and sodium oxide.Each of these chemicals reacts with other substances like water or carbon dioxide to produce different products.

• For example, sodium peroxide (\( \mathrm{Na}_2 \mathrm{O}_2 \)) with water produces sodium hydroxide and oxygen gas.
• Similarly, potassium superoxide (\( \mathrm{KO}_2 \)) when reacted with water yields potassium hydroxide, oxygen gas, and hydrogen peroxide.
• Sodium oxide reacts with carbon dioxide to form sodium carbonate.

These transformations underline the importance of knowing how compounds react, to anticipate their effects and applications in various chemical contexts.

Sodium Peroxide

Sodium peroxide, \( \mathrm{Na}_2 \mathrm{O}_2 \), is a yellowish solid compound primarily used as an oxidation agent. It plays a significant role in reactions with water, as seen in its reaction:\[2 \mathrm{Na}_2 \mathrm{O}_2 + 2 \mathrm{H}_2 \mathrm{O} \rightarrow 4 \mathrm{NaOH} + \mathrm{O}_2\]In this reaction, sodium peroxide reacts with water to form sodium hydroxide (\( \mathrm{NaOH} \)) and oxygen gas (\( \mathrm{O}_2 \)). Sodium peroxide has its primary commercial use in bleaching and decolorizing fibers and in producing oxygen.When handling sodium peroxide, it is essential to take precautions due to its reactive nature, especially when it comes in contact with water. This understanding of its properties and reactions is crucial for applications in industrial processes and laboratory experiments.

Potassium Superoxide

Potassium superoxide, with the chemical formula \( \mathrm{KO}_2 \), is a potent oxidizing agent that reacts vigorously with water. Its use is primarily in closed air environments, such as submarines and space habitats, where it serves to regenerate oxygen.In the typical reaction with water:\[4 \mathrm{KO}_2 + 2 \mathrm{H}_2 \mathrm{O} \rightarrow 4 \mathrm{KOH} + 3 \mathrm{O}_2 + \mathrm{H}_2 \mathrm{O}_2\]Potassium superoxide reacts to release oxygen, produce potassium hydroxide (\( \mathrm{KOH} \)), and form hydrogen peroxide (\( \mathrm{H}_2 \mathrm{O}_2 \)). This property makes it exceptionally useful for maintaining breathable air by absorbing carbon dioxide and moisture while releasing oxygen. Given its high reactivity, careful handling of potassium superoxide is important to prevent accidental combustion or explosion.

Sodium Oxide

Sodium oxide (\( \mathrm{Na}_2 \mathrm{O} \)) is a white solid used widely in the manufacturing of glass and ceramics. It reacts with carbon dioxide (\( \mathrm{CO}_2 \)) to form sodium carbonate (\( \mathrm{Na}_2 \mathrm{CO}_3 \)).The reaction can be outlined simply as:\[\mathrm{Na}_2 \mathrm{O} + \mathrm{CO}_2 \rightarrow \mathrm{Na}_2 \mathrm{CO}_3\]This balanced chemical equation is straightforward but critical in industrial settings like soda glass production, where sodium carbonate enhances glass properties. Notably, sodium oxide itself is seldom seen in isolation since it reacts readily with moisture to form sodium hydroxide, highlighting its reactive nature.Understanding sodium oxide's behaviors and reactions assists in its effective implementation in industrial processes, making balancing these reactions a key skill for chemists.