The ratio of nitrogen to water by mass in a molecule of nitrogen gas (N2) and water (H2O) is 14:9.
Here's a detailed explanation:
Understanding Molecular Mass
To calculate the mass ratio, we need to understand the atomic masses of the elements involved:
- Nitrogen (N): Atomic mass of approximately 14 atomic mass units (amu).
- Hydrogen (H): Atomic mass of approximately 1 amu.
- Oxygen (O): Atomic mass of approximately 16 amu.
Calculating the Ratio
We analyze the ratio in terms of the molecular forms N2 (nitrogen gas) and H2O (water).
Here is how we calculate the ratio of their molecular masses:
- Nitrogen (N2):
- A nitrogen molecule consists of two nitrogen atoms (N2).
- The molecular mass of N2 is 2 * 14 amu = 28 amu.
- Water (H2O):
- A water molecule consists of two hydrogen atoms and one oxygen atom.
- The molecular mass of H2O is (2 1 amu) + (1 16 amu) = 18 amu.
- Ratio:
- The mass ratio of N2 to H2O is 28:18.
- Simplifying the ratio by dividing both numbers by 2, we obtain 14:9.
Summary Table
| Molecule | Atoms | Molecular Mass (amu) | Simplified Ratio with Water |
|---|---|---|---|
| N2 | 2 N | 28 | 14 |
| H2O | 2 H, 1 O | 18 | 9 |
Therefore, the ratio of nitrogen to water by mass, specifically for one molecule of each compound, is 14:9.
