Calculating the Number of Molecules of NH3 Produced from H2

In this article, we will explore how to determine the number of molecules of NH3 (ammonia) produced from a given mass of H2 (hydrogen gas) using stoichiometric principles.

Understanding the Reaction

The reaction for the formation of ammonia (NH3) from hydrogen gas (H2) and nitrogen gas (N2) is:

N2 + 3H2 → 2NH3

This balanced chemical equation tells us that for every 1 molecule of N2 and 3 molecules of H2 that react, 2 molecules of NH3 are produced.

Calculating the Number of Molecules of NH3

Given:

• Mass of H2 = 3.86 × 10^-4 g

To find the number of molecules of NH3 produced, we'll need to follow these steps:

1. Convert the mass of H2 to moles of H2:

• Moles of H2 = Mass of H2 / Molar mass of H2
• Molar mass of H2 = 2.02 g/mol
• Moles of H2 = (3.86 × 10^-4 g) / (2.02 g/mol) = 1.91 × 10^-4 mol

1. Convert the moles of H2 to moles of NH3:

• According to the balanced equation, for every 3 moles of H2, 2 moles of NH3 are produced.
• Moles of NH3 = (2/3) × Moles of H2
• Moles of NH3 = (2/3) × 1.91 × 10^-4 mol = 1.27 × 10^-4 mol

1. Convert the moles of NH3 to the number of molecules of NH3:

• Number of molecules of NH3 = Moles of NH3 × Avogadro's number
• Avogadro's number = 6.022 × 10^23 molecules/mol
• Number of molecules of NH3 = (1.27 × 10^-4 mol) × (6.022 × 10^23 molecules/mol) = 7.65 × 10^19 molecules

Therefore, the number of molecules of NH3 produced from 3.86 × 10^-4 g of H2 is 7.65 × 10^19 molecules.