How to Calculate the Number of Moles of Nitric Acid from Oxygen Atoms

Understanding the Relationship Between Oxygen Atoms and Nitric Acid

Nitric acid (HNO₃) has the chemical formula HNO₃, where there are three oxygen (O) atoms in each molecule of nitric acid. To calculate the number of moles of nitric acid from a given number of oxygen atoms, we need to follow a specific process.

Steps to Determine the Moles of Nitric Acid

1. Identify the Given Data: Determine the number of oxygen atoms in the sample, such as 3.55x10²³ atoms of O.

2. Calculate Moles of Oxygen: Use Avogadro's number (6.022x10²³ atoms/mol) to find the moles of oxygen atoms in the sample.

3. Apply the Molar Ratio: Since each molecule of nitric acid contains three oxygen atoms, divide the moles of oxygen by three to get the moles of nitric acid.

4. Finalize the Calculation: Round the result to determine the approximate number of moles of nitric acid present.

Example Calculation:

Given: 3.55x10²³ atoms of O

Moles of O = (3.55x10²³ atoms O) / (6.022x10²³ atoms/mol) ≈ 0.589 moles of O

Moles of HNO₃ = (0.589 moles of O) / 3 ≈ 0.196 moles of HNO₃

Therefore, when provided with 3.55x10²³ atoms of oxygen in a sample, there are approximately 0.196 moles of nitric acid present.