Question

place the coefficients that correctly balance the chemical equation. answer choices may be used only once.
fe₂o₃ + c ----> 4fe + 3co₂
answer choices (with numbers 1,2; 2,4; 3,3; 4,1) are provided on the left.

Explanation:

Step1: Balance Fe atoms

On the right, there are 4 Fe atoms. In \( \text{Fe}_2\text{O}_3 \), each molecule has 2 Fe atoms. So, to get 4 Fe atoms, we need \( \frac{4}{2} = 2 \) molecules of \( \text{Fe}_2\text{O}_3 \). So the coefficient for \( \text{Fe}_2\text{O}_3 \) is 2.

Step2: Balance O atoms

In 2 \( \text{Fe}_2\text{O}_3 \), the number of O atoms is \( 2\times3 = 6 \). On the right, each \( \text{CO}_2 \) has 2 O atoms, and there are 3 \( \text{CO}_2 \) molecules, so total O on right is \( 3\times2 = 6 \), which matches. Now balance C atoms. On the right, there are 3 C atoms (from 3 \( \text{CO}_2 \)), so we need 3 C atoms on the left. So the coefficient for C is 3.

Answer:

For \( \text{Fe}_2\text{O}_3 \): 2; For C: 3