Question

select the correct answer.

iron reacts with atmospheric oxygen to form iron oxide or ferric oxide. look at the chemical equation for this reaction:

fe + o₂ → fe₂o₃

this equation is unbalanced. which of the following is the correct balanced equation for this reaction?

a. 4fe + 3o₂ → 2fe₂o₃

b. 3fe + 4o₂ → 2fe₂o₃

c. 2fe + 4o₂ → 3fe₂o₃

d. 3fe + 3o₂ → 4fe₂o₃

e. 4fe + 4o₂ → 3fe₂o₃

Explanation:

Step1: Analyze Fe atoms

In the unbalanced equation \( \text{Fe} + \text{O}_2
ightarrow \text{Fe}_2\text{O}_3 \), on the right side, each \( \text{Fe}_2\text{O}_3 \) has 2 Fe atoms. Let's check each option for Fe balance.

• Option A: Left Fe = 4, Right Fe = \( 2\times2 = 4 \) (balanced for Fe).
• Option B: Left Fe = 3, Right Fe = \( 2\times2 = 4 \) (not balanced).
• Option C: Left Fe = 2, Right Fe = \( 3\times2 = 6 \) (not balanced).
• Option D: Left Fe = 3, Right Fe = \( 4\times2 = 8 \) (not balanced).
• Option E: Left Fe = 4, Right Fe = \( 3\times2 = 6 \) (not balanced).

Step2: Analyze O atoms (for Option A)

Left O: \( 3\times2 = 6 \), Right O: \( 2\times3 = 6 \) (balanced for O).

Answer:

A. \( 4\text{Fe} + 3\text{O}_2
ightarrow 2\text{Fe}_2\text{O}_3 \)