Problem 68 - 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) \( 2BaO + O_2 \rightarrow 2BaO_2 \) (b) \( 4Fe + 3BaO_2 \rightarrow 2Fe_2O_3 + 3BaO \)

Step 1: Determine the Reactants and Products for Part (a)

For the reaction of barium oxide with oxygen to form barium peroxide, identify the reactants: barium oxide (BaO) and oxygen \( O_2 \). The product is barium peroxide \( BaO_2 \).

Step 2: Write the Unbalanced Equation for Part (a)

Write down the chemical equation using chemical formulas: \[ BaO + O_2 \rightarrow BaO_2 \]

Step 3: Balance the Equation for Part (a)

Balance the equation by ensuring the number of atoms for each element is the same on both sides. The balanced equation is: \[ 2BaO + O_2 \rightarrow 2BaO_2 \]

Step 4: Identify Reactants and Products for Part (b)

For the reaction of iron with barium peroxide, the reactants are iron \( Fe \) and barium peroxide \( BaO_2 \). The products are iron (III) oxide \( Fe_2O_3 \) and barium oxide \( BaO \).

Step 5: Write the Unbalanced Equation for Part (b)

Translate the word description into chemical symbols and formulas:\[ Fe + BaO_2 \rightarrow Fe_2O_3 + BaO \]

Step 6: Balance the Equation for Part (b)

Balance the elements in the reaction. The balanced equation is: \[ 4Fe + 3BaO_2 \rightarrow 2Fe_2O_3 + 3BaO \]

Key Concepts

Balancing Chemical Reactions

Balancing reactions is a key skill in chemistry that ensures the law of conservation of mass is respected. In a chemical equation, the number of atoms for each element must be the same on both sides of the equation, meaning what you start with must equal what you end with. The process can be thought of as being similar to solving a puzzle where every atom finds its correct place.

When balancing, remember:

• Check each element individually.
• Start with elements that appear in only one reactant and one product, and save H and O for last.
• Use coefficients to multiply the entire formula to achieve balance.

In the reactions provided, barium oxide reacts with oxygen to form barium peroxide, requiring careful balancing of oxygen atoms as seen in Step 3. Similarly, in the reaction involving iron and barium peroxide, both reactants and products required adjustment of coefficients to reflect equal numbers of each atom on both sides as shown in Step 6.

Oxidizing Agents

Oxidizing agents are substances that can accept electrons during a chemical reaction. Essentially, they get reduced while facilitating the oxidation of another substance. Comprehending the role of oxidizing agents is crucial when exploring redox reactions in chemistry.

Barium peroxide, in this example, serves as an oxidizing agent. It delivers oxygen to another substance and, in the process, gets reduced to barium oxide. When iron reacts with barium peroxide, it results in the oxidization of iron to iron (III) oxide, while the barium peroxide itself is reduced.

Key points include:

• Oxidizing agents cause another substance to oxidize (lose electrons).
• They are typically involved in transferring oxygen or gaining electrons.
• Reduce as they oxidize another material.

Here, the reaction transforms chemical states, showing the dual role of barium peroxide.

Stoichiometry

Stoichiometry involves the calculation of reactants and products in chemical reactions. It allows chemists to predict how much of a substance is needed or produced. Understanding stoichiometry is critical for deep insights into chemical processes and efficient resource usage.

This concept calculates the precise amounts of each reactant needed to form specified products as seen in the given balanced equations. In part (a), two moles of barium oxide react with one mole of oxygen to produce two moles of barium peroxide.

When addressing stoichiometry:

• Use the balanced equation as a calculation map.
• Understand mole ratios from the equation coefficients.
• Transform these ratios to actual quantities using molar mass.

For example, in part (b), stoichiometry dictates that four moles of iron react with three moles of barium peroxide, yielding two moles of iron (III) oxide and three moles of barium oxide. This accurate accounting ensures efficient chemical reaction management.