Question

Find out the oxidation state of sodium in \(\mathrm{Na}_{2} \mathrm{O}_{2}\).

Short answer

The oxidation state of sodium in \(\mathrm{Na}_2 \mathrm{O}_2\) is \(+1\).

Step-by-step solution

Understanding the Compound

Sodium peroxide, denoted as \(\mathrm{Na}_2 \mathrm{O}_2\), contains sodium atoms and peroxide ions as a compound. Our goal is to find the oxidation state of sodium in this compound.

The Peroxide Ion Attribute

A peroxide ion, \( \mathrm{O}_2^{2-} \), contains two oxygen atoms. Typically, in peroxides, each oxygen in the \( \mathrm{O}_2^{2-} \) ion exhibits an oxidation state of \(-1\), contrasting with the \(-2\) oxidation state observed in most other oxygen-containing compounds.

Setting Up an Equation

Within one molecule of \(\mathrm{Na}_2 \mathrm{O}_2 \), we compute the total oxidation states. Let the oxidation state of sodium (\(\mathrm{Na}\)) be \(x\). There are two sodium atoms:\[2(x) + 2(-1) = 0\] This equation arises because the compound \(\mathrm{Na}_2 \mathrm{O}_2\) is neutral.

Solving for the Oxidation State

Solve the equation from the previous step: \[2x - 2 = 0\] Add 2 to both sides: \[2x = 2\] Divide by 2 to isolate \(x\): \[x = 1\] The oxidation state of sodium in \(\mathrm{Na}_2 \mathrm{O}_2\) is \(+1\).

Key concepts

Sodium Peroxide

Sodium peroxide is a chemical compound with the formula \( \mathrm{Na}_2 \mathrm{O}_2 \). It consists of sodium (Na) and the peroxide ion \( (\mathrm{O}_2^{2-}) \). Sodium is an alkali metal, found in group 1 of the periodic table, and typically forms compounds where it has a \(+1\) oxidation state. In sodium peroxide, the key player is the peroxide ion, which influences the overall charge and structure of the compound.
A distinctive trait of sodium peroxide, compared to other sodium oxides, is how it contains the peroxide ion instead of simple oxide ions \( (\mathrm{O}^{2-}) \). This presence of the peroxide ion, with each oxygen having an unusual oxidation state of \(-1\), makes sodium peroxide unique in both chemical structure and reactivity. It is used in various applications like bleaching, chemical oxygen generation, and as a laboratory reagent. Understanding sodium peroxide involves recognizing its mixture of a typical positive oxidative component (sodium) and a special peroxide group.

Peroxides

Peroxides are a classification of compounds characterized by the presence of an \( \mathrm{O}_2^{2-} \) ion, also known as the peroxide ion. This group of compounds showcases a unique bond where the two oxygen atoms are linked by a single bond. In a peroxide ion, every oxygen atom holds an oxidation state of \(-1\), which is different from its typical \(-2\) state found when oxygen is fully reduced, like in water.
Understanding peroxides' characteristics help highlight why they're distinct from typical oxides. They often act as oxidizing agents due to this distinct oxidation state configuration. It is important to note that peroxides exist in many forms, not only as alkaline metal peroxides, such as sodium peroxide, but also in organic peroxides which are sensitive compounds often used in industry as initiators for polymerization.
Recognizing their structural uniqueness and chemical properties is essential in understanding their roles in chemical reactions and real-world applications.

Neutral Compounds

Neutral compounds are chemical structures where the total positive and negative charges balance each other out, resulting in no overall charge. Understanding that sodium peroxide \( \mathrm{Na}_2 \mathrm{O}_2 \) is neutral helps clarify its balancing act between components. Sodium has a known oxidation state of \(+1\), while each oxygen in the peroxide ion has an oxidation state of \(-1\).
In the compound \( \mathrm{Na}_2 \mathrm{O}_2 \), there are two sodium atoms contributing a total of \(+2\), and the peroxide ion \( \mathrm{O}_2^{2-} \) contributes \(-2\). These add up to zero, confirming the neutrality of the compound. This neutrality is crucial for predicting how it will behave chemically. Many reactions and properties of compounds derive from whether they are neutral, positively charged, or negatively charged. Understanding the charge neutrality principle can also aid chemistry students in determining oxidation states, chemical stability, and potential reaction pathways.