Determine the Empirical Formula of Iron Oxide in a Chemical Reaction

The empirical formula of a compound represents the simplest whole-number ratio of the elements in that compound. In this article, we will walk through the process of determining the empirical formula of iron oxide through a chemical reaction involving iron oxide and hydrogen. We will cover calculations and reasoning to arrive at the correct empirical formula.

Problem Statement

Given: 3.2 grams of iron oxide are heated with hydrogen, resulting in the production of 2.24 grams of iron (Fe). The objective is to determine the empirical formula of the iron oxide produced in this reaction.

Step-by-Step Solution

1. Calculate the Moles of Iron Produced

First, we need to convert the mass of iron to moles using the molar mass of iron.

Moles of Fe frac{2.24 text{g}}{55.85 text{g/mol}} 0.0400 text{mol}

2. Determine the Moles of Iron Oxide (Fe?O?) Used

The iron oxide used is assumed to be Fe?O?, the most common form of iron oxide. We need to calculate the moles of Fe?O? from the mass given.

Molar Mass of Fe?O? (55.85 × 2) (16.00 × 3) 111.7 48.00 159.7 g/mol

Moles of Fe?O? frac{3.2 text{g}}{159.7 text{g/mol}} 0.0200 text{mol}

3. Determine the Ratio of Moles

In the reaction of Fe?O? with hydrogen, each mole of Fe?O? produces 2 moles of Fe. Therefore, we can calculate the moles of Fe produced from Fe?O?.

Moles of Fe produced from Fe?O? 0.0200 mol × 2 0.0400 mol

This ratio is consistent with the empirical formula of iron (Fe) being simply Fe, as it is a pure element and does not combine with any other elements in its elemental form.

4. Corrected Solution with Correct Metric Abbreviations

Given mass of Fe 2.24 g

Mass of O 3.20 - 2.24 0.96 g

Divide each mass by the molar mass of the element:

Fe 2.24 g / 55.85 g/mol 0.040

O 0.96 g / 16 g/mol 0.06

Divide through by the smaller value:

Fe 1

O 1.5

Remove the fraction by multiplying by 2:

Fe 2

O 3

Therefore, the empirical formula for the iron oxide is Fe?O?.

Conclusion

The empirical formula of iron oxide in this reaction is Fe?O?. Understanding the empirical formula is crucial for analyzing and interpreting chemical reactions, and it reflects the simplest whole-number ratio of the elements involved.

Key Points

Empirical formula: Represents the simplest whole-number ratio of the elements in a compound. Iron oxide (Fe?O?): Common form of iron oxide used in chemical reactions.

By following the steps outlined above, we can accurately determine the empirical formula of iron oxide and understand the underlying principles of chemical reactions.