Question

Write the chemical equation for the reaction between (a) sodium and oxygen; (b) lithium and nitrogen; (c) sodium and water; (d) potassium superaxide and water.

Short answer

(a) \(4\text{Na} + \text{O}_2 \rightarrow 2\text{Na}_2\text{O}\); (b) \(6\text{Li} + \text{N}_2 \rightarrow 2\text{Li}_3\text{N}\); (c) \(2\text{Na} + 2\text{H}_2\text{O} \rightarrow 2\text{NaOH} + \text{H}_2\); (d) \(4\text{KO}_2 + 2\text{H}_2\text{O} \rightarrow 4\text{KOH} + 3\text{O}_2 + 2\text{H}_2\text{O}_2\).

Step-by-step solution

Sodium and Oxygen Reaction

Determine the reactants and products. Sodium (\text{Na}) reacts with oxygen (\text{O}_2) to form sodium oxide (\text{Na}_2\text{O}). Balance the chemical equation by ensuring the same number of each type of atom on both sides of the equation. The balanced chemical equation is: \[4\text{Na} + \text{O}_2 \rightarrow 2\text{Na}_2\text{O}\]

Lithium and Nitrogen Reaction

Identify the reactants and products. Lithium (\text{Li}) reacts with nitrogen (\text{N}_2) to form lithium nitride (\text{Li}_3\text{N}). Balance the chemical equation by ensuring that there are equal numbers of each type of atom on both sides of the equation. The balanced equation is: \[6\text{Li} + \text{N}_2 \rightarrow 2\text{Li}_3\text{N}\]

Sodium and Water Reaction

Determine the reactants and products. Sodium (\text{Na}) reacts with water (\text{H}_2\text{O}) to produce sodium hydroxide (\text{NaOH}) and hydrogen gas (\text{H}_2). Balance the chemical equation to maintain the law of conservation of mass. The balanced chemical equation is: \[2\text{Na} + 2\text{H}_2\text{O} \rightarrow 2\text{NaOH} + \text{H}_2\]

Potassium Superoxide and Water Reaction

Identify reactants and products. Potassium superoxide (\text{KO}_2) reacts with water (\text{H}_2\text{O}) to form potassium hydroxide (\text{KOH}), oxygen (\text{O}_2), and hydrogen peroxide (\text{H}_2\text{O}_2). To balance the equation, ensure equal numbers of each type of atom on both sides. The balanced equation is: \[4\text{KO}_2 + 2\text{H}_2\text{O} \rightarrow 4\text{KOH} + 3\text{O}_2 + 2\text{H}_2\text{O}_2\]

Key concepts

Balancing Chemical Equations

The delicate art of balancing chemical equations lies at the heart of chemistry, ensuring that the law of conservation of mass is upheld. Simply put, what goes into a chemical reaction must equal what comes out. For example, when sodium (\text{Na}) combines with oxygen (\text{O}_2), we get sodium oxide (\text{Na}_2\text{O}). To balance this reaction, you need to ensure that the number of sodium and oxygen atoms is the same on both sides. The balanced representation of this reaction is: \[\begin{equation}4\text{Na} + \text{O}_2 \rightarrow 2\text{Na}_2\text{O}ewline\end{equation}\] In a nutshell, balancing chemical equations involves tweaking the coefficients (the numbers before the chemical formulas) to get the same number of each type of atom on both sides of the reaction arrow.

Reaction Stoichiometry

Reaction stoichiometry can be thought of as the recipe for a chemical reaction, detailing the exact proportions of reactants needed to generate desired products. It tells us not just what substances react, but how much of each substance is involved. For instance, in the reaction between lithium (\text{Li}) and nitrogen (\text{N}_2) to yield lithium nitride (\text{Li}_3\text{N}), stoichiometry comes into play to balance the equation as: \[\begin{equation}6\text{Li} + \text{N}_2 \rightarrow 2\text{Li}_3\text{N}ewline\end{equation}\] Reaction stoichiometry is crucial for understanding the quantities involved in a reaction, which is important in both laboratory work and industrial processes. If we don't know the correct proportions, we can't produce compounds efficiently or predict the outcome of reactions.

Alkali Metal Reactions

Alkali metals, such as sodium (\text{Na}) and potassium (\text{K}), are known for their vigorous reactions with other substances, including water. When sodium reacts with water, it forms sodium hydroxide (\text{NaOH}) and hydrogen gas (\text{H}_2), as shown in the equation:\[\begin{equation}2\text{Na} + 2\text{H}_2\text{O} \rightarrow 2\text{NaOH} + \text{H}_2ewline\end{equation}\] These reactions are highly exothermic, releasing a significant amount of heat. They're a perfect illustration of the reactivity of alkali metals, and understanding these reactions is fundamental for further studies in inorganic chemistry and safety procedures in chemical handling.

Inorganic Chemistry

Inorganic chemistry is the branch of chemistry concerned with the properties and behaviors of inorganic compounds, which are compounds not containing carbon atoms. This field covers a vast range of substances, including metals, minerals, and organometallic compounds. The reaction between potassium superoxide (\text{KO}_2) and water is an interesting example from inorganic chemistry. This reaction forms potassium hydroxide (\text{KOH}), oxygen (\text{O}_2), and hydrogen peroxide (\text{H}_2\text{O}_2), as captured in the balanced equation:\[\begin{equation}4\text{KO}_2 + 2\text{H}_2\text{O} \rightarrow 4\text{KOH} + 3\text{O}_2 + 2\text{H}_2\text{O}_2ewline\end{equation}\] Such reactions highlight the diversity of inorganic compounds and their transformations, as well as the importance of understanding their behavior for applications in various fields, from environmental to industrial.