Problem 75 - Chemistry and Chemical Reactivity

Question

(a) Heating barium oxide in pure oxygen gives barium peroxide. Write a balanced equation for this reaction. (b) Barium peroxide is an excellent oxidizing agent. Write a balanced equation for the reaction of iron with barium peroxide to give iron(III) oxide and barium oxide.

Step-by-Step Solution

Answer

(a) \( 2\text{BaO} + \text{O}_2 \rightarrow 2\text{BaO}_2 \); (b) \( 2\text{Fe} + 3\text{BaO}_2 \rightarrow \text{Fe}_2\text{O}_3 + 3\text{BaO} \).

Step 1: Identify Reactants and Products for Reaction (a)

For the reaction of barium oxide (BaO) with oxygen, the products are barium peroxide (BaO_2).**Reactants:** \( \text{BaO} + \text{O}_2 \)**Products:** \( \text{BaO}_2 \)

Step 2: Balance the Equation for Reaction (a)

The unbalanced reaction is:\[ \text{BaO} + \text{O}_2 \rightarrow \text{BaO}_2 \]Each side of the equation must have the same number of each type of atom. Considering the stoichiometry:Since oxygen appears as a diatomic molecule and in the compound \( \text{BaO}_2 \), balance barium and oxygen as follows:\[ 2\text{BaO} + \text{O}_2 \rightarrow 2\text{BaO}_2 \] This equation shows 2 barium atoms and 4 oxygen atoms on each side, indicating it is balanced.

Step 3: Identify Reactants and Products for Reaction (b)

In the reaction of iron with barium peroxide, the products are barium oxide and iron(III) oxide.**Reactants:** \( \text{Fe} + \text{BaO}_2 \)**Products:** \( \text{Fe}_2\text{O}_3 + \text{BaO} \)

Step 4: Balance the Equation for Reaction (b)

The unbalanced reaction is:\[ \text{Fe} + \text{BaO}_2 \rightarrow \text{Fe}_2\text{O}_3 + \text{BaO} \]First, balance the iron atoms:- 2 iron atoms in \( \text{Fe}_2\text{O}_3 \), so put a coefficient of 2 before \( \text{Fe} \): \[ 2\text{Fe} + \text{BaO}_2 \rightarrow \text{Fe}_2\text{O}_3 + \text{BaO} \] Next, balance the barium atoms:- Since each barium from \( \text{BaO}_2 \) becomes \( \text{BaO} \), they are already balanced with a coefficient of 1.Finally, balance the oxygen atoms:- On the right, 3 (from \( \text{Fe}_2\text{O}_3 \)) plus 1 (from \( \text{BaO} \)) = 4. Therefore, put a coefficient of 3 in front of \( \text{BaO}_2 \) to make six oxygens: \[ 2\text{Fe} + 3\text{BaO}_2 \rightarrow \text{Fe}_2\text{O}_3 + 3\text{BaO} \] Check:- 2 iron, 3 barium, and 6 oxygen atoms on both sides, so the equation is balanced.

Key Concepts

Oxidizing Agents

Oxidizing agents are chemicals that promote oxidation, which involves the loss of electrons by another substance. In simpler terms, they help others in gaining oxygen or losing electrons.
Barium peroxide (\( \text{BaO}_2 \)) is a strong oxidizing agent. It readily supplies oxygen to other substances, which is particularly useful in various chemical reactions, including the transformation of iron to iron(III) oxide.
This role makes barium peroxide valuable in industries as it can help ignite or speed up reactions by providing necessary oxygen to fuel the process. Remember, the more efficiently an oxidizing agent transfers oxygen, the stronger it is considered to be. Hence, barium peroxide's effectiveness is rooted in its reactivity and ability to decompose, providing oxygen when needed.

Stoichiometry

Stoichiometry is the area of chemistry that concerns the proportional relationships between reactants and products in chemical reactions. It involves the use of ratios derived from balanced equations to calculate amounts.
When balancing a chemical equation, stoichiometry ensures that the same number of each type of atom exists on both sides of the equation. This method uses coefficients to indicate the relative amounts of each substance.
For example, in the reaction where barium oxide reacts with oxygen to form barium peroxide, we balance by using coefficients: \[ 2\text{BaO} + \text{O}_2 \rightarrow 2\text{BaO}_2 \]
Balancing ensures adherence to the conservation of mass, meaning atoms are neither created nor destroyed during the reaction. Stoichiometry enables chemists to predict the amounts of products formed in a given reaction from known quantities of reactants.

Barium Compounds

Barium compounds are versatile chemicals used in the chemical industry. Barium itself is a soft metallic element, and its compounds often exhibit interesting properties.
In the context of the exercise, we encounter both barium oxide (\( \text{BaO} \)) and barium peroxide (\( \text{BaO}_2 \)).

• Barium oxide is a basic oxide in solid form, used mainly in ceramics and glassmaking.
• Barium peroxide, on the other hand, is used for its oxidizing capabilities.

The transformation between these two compounds occurs through the reaction with oxygen, demonstrating how the structure of barium compounds can adapt based on their chemical environment. Barium compounds are integral in applications ranging from the manufacturing of specific glasses to their roles in chemical reactions, like serving as oxidizers to support combustion.