Determine the Mass of Iron(III) Oxide Produced in the Decomposition of Iron(III) Hydroxide

The decomposition of iron(III) hydroxide, Fe(OH)3, when heated can be represented by the following balanced chemical equation:

2Fe(OH)3 → Fe2O3 3H2O

This reaction is a prime example of a chemical decomposition process. To determine the mass of iron(III) oxide, Fe2O3, produced from 100.0 grams of iron(III) hydroxide, we can follow a systematic approach using stoichiometry.

Step 1: Convert Given Information to Moles

The first step in solving this problem is to calculate the number of moles of iron(III) hydroxide present. The molar mass of Fe(OH)3 can be calculated based on the atomic masses of iron (Fe) and hydrogen (H) and the molar mass of oxygen (O).

Molar mass of Fe(OH)3 55.85 g/mol (Fe) 3 × (1.01 g/mol (H) 16.00 g/mol (O)) 106.867 g/mol

Using the given mass of iron(III) hydroxide:

N(Fe(OH)3) (frac{100.0 text{g}}{106.867 text{g/mol}}) 0.9357 mol Fe(OH)3

Step 2: Use the Mole Ratio to Find Moles of Desired Substance

The next step is to use the mole ratio from the balanced equation to find the moles of iron(III) oxide produced. The balanced equation shows that 2 moles of Fe(OH)3 decompose to form 1 mole of Fe2O3 and 3 moles of water.

N(Fe2O3) 0.9357 mol Fe(OH)3 × (frac{1 text{mol Fe}_2text{O}_3}{2 text{mol Fe(OH)}_3}) 0.4679 mol Fe2O3

Step 3: Convert Moles of Desired Substance to Required Units

The final step is to convert the moles of iron(III) oxide to mass in grams, using the molar mass of Fe2O3, which is 159.7 g/mol.

M(Fe2O3) 0.4679 mol × 159.7 g/mol 74.71 g Fe2O3

Conclusion

Hence, when 100.0 grams of iron(III) hydroxide is decomposed, 74.71 grams of iron(III) oxide are produced. This approach, known as stoichiometry, allows us to accurately predict the products and their quantities in chemical reactions. By understanding the balanced equation and applying the principles of stoichiometry, we can solve a wide range of chemistry problems efficiently.

Related Keywords

stoichiometry, chemical reaction, mass calculation