Determining Moles of Water Produced from Hydrogen Combustion

Understanding the chemical process of hydrogen combustion is crucial for various applications in chemistry and engineering. This article explores the calculation of moles of water produced from the combustion of 10.00 grams of hydrogen. We will delve into the chemical equation, conversion methods, and key concepts, including Avogadro's number and stoichiometry.

Chemical Equation and Stoichiometry

The balanced chemical equation for the combustion of hydrogen gas with oxygen is:

2H2 O2 → 2H2O

This equation tells us that 2 moles of hydrogen gas (H2) react with 1 mole of oxygen gas (O2) to produce 2 moles of water (H2O). Therefore, let's determine the moles of water produced from 10.00 grams of hydrogen.

Step-by-Step Calculation

1. **Determine the moles of hydrogen gas (H2):**

10 g H2 × (1 mol H2 / 2.016 g H2) 4.96 mol H2

2. **Use the stoichiometry to find the moles of water (H2O) produced:**

4.96 mol H2 × (2 mol H2O / 2 mol H2) 4.96 mol H2O

3. **Convert moles of water to grams:**

4.96 mol H2O × 18.01528 g/mol H2O 89.32 g H2O

Thus, 10.00 grams of hydrogen produce approximately 89.32 grams of water.

Understanding Avogadro's Number and Atomic Level

It's important to clarify the distinction between moles of hydrogen atoms (H) and moles of hydrogen molecules (H2). One mole of any substance contains Avogadro's number of particles (6.022 × 1023). In this context, 10 moles of H2O require 20 moles of H atoms to form, based on the structure H-H in H2 and the formula H2O.

Example Calculations

1. **Using a simpler method: 2H2 O2 → 2H2O**

? moles (H2) × (2 moles H2O / 2 moles H2) 10 moles H2O

2. **Direct conversion example: 13.2 g H2/2 g, 6.6 moles of H2O**

13.2 g H2 × (18.01528 g H2O / 2 g H2) 118.8 g H2O 6.6 moles H2O

3. **Using the balanced equation: 2H2 O2 → 2H2O**

13.2 g H2 × (1 mol H2 / 2.016 g H2) × (2 mol H2O / 1 mol H2) 6.6 moles H2O

Formation of Water from Its Elements

The formation of water from its elements hydrogen and oxygen can be described by the following stoichiometric equation:

2H2 O2 → 2H2O

From the equation, one mole of dihydrogen (H2) reacts with half a mole of dioxygen (O2) to produce one mole of water (H2O). Given 6.5 moles of dihydrogen, the stoichiometry dictates that 6.5 moles of water are produced. This also answers the question regarding the moles of dioxygen required.

Conclusion

Understanding the chemical equation and the use of stoichiometry and Avogadro's number is key to solving problems related to the combustion of hydrogen and the formation of water. The calculations presented here help in determining the exact moles and grams of water produced from a given mass of hydrogen, facilitating a deeper understanding of chemical reactions and their practical applications.

Keywords: hydrogen combustion, moles of water, chemical equation