Question

1. the formation of rust is described in the following statement. four moles of iron metal react with three moles of oxygen gas to produce two moles of solid iron (iii) oxide. what is the balanced equation for the formation of rust?

4 fe (s) + 3 o₂ (g) → 2 fe₃o (s)
fe₄ (s) + o₃ (g) → fe₃o₂ (s)
fe₄ (s) + o₃ (g) → fe₂o₃ (s)
4 fe (s) + 3 o₂ (g) → 2 fe₂o₃ (s)
clear all

Explanation:

Step1: Identify reactants/products

Reactants: Fe (iron), $\text{O}_2$ (oxygen gas). Product: Iron(III) oxide, formula $\text{Fe}_2\text{O}_3$ (since Fe³⁺ and O²⁻ form neutral compound).

Step2: Match mole ratios

Problem states 4 mol Fe, 3 mol $\text{O}_2$ produce 2 mol product. Check atom balance:

• Fe: Left $4$, Right $2\times2=4$
• O: Left $3\times2=6$, Right $2\times3=6$

Step3: Verify correct option

Only the last option uses correct formula for iron(III) oxide and matches the given mole ratios with balanced atoms.

Answer:

D. $4 \text{ Fe (s)} + 3 \text{ O}_2 \text{ (g)}
ightarrow 2 \text{ Fe}_2\text{O}_3 \text{ (s)}$