The mass of nitrogen per grams in hydrazine is exactly one and half the mass of nitrogen in the compound ammonia. The fact illustrates the

Options

A. Law of conservation of mass
B. Multiple valency of nitrogen
C. Law of multiple proportion
D. Law of definite proportion.

Answer

To solve the question, we need to analyze the relationship between the masses of nitrogen in hydrazine (N2H4) and ammonia (NH3) and understand the concept illustrated by this relationship.

### Step-by-Step Solution:

1. **Identify the Compounds**:
- The compounds in question are hydrazine (N2H4) and ammonia (NH3).

2. **Determine the Molar Mass of Nitrogen**:
- The atomic mass of nitrogen (N) is approximately 14 g/mol.

3. **Calculate the Mass of Nitrogen in Each Compound**:
- For ammonia (NH3):
- There is 1 nitrogen atom, so the mass of nitrogen in NH3 = 1 × 14 g/mol = 14 g.
- For hydrazine (N2H4):
- There are 2 nitrogen atoms, so the mass of nitrogen in N2H4 = 2 × 14 g/mol = 28 g.

4. **Compare the Masses of Nitrogen**:
- According to the question, the mass of nitrogen in hydrazine is one and a half times the mass of nitrogen in ammonia.
- We can express this mathematically:
- Mass of nitrogen in hydrazine = 1.5 × Mass of nitrogen in ammonia.
- 28 g = 1.5 × 14 g.
- This equation holds true, confirming the relationship.

5. **Illustrate the Law of Multiple Proportions**:
- The law of multiple proportions states that when two elements combine to form more than one compound, the ratios of the masses of one element that combine with a fixed mass of the other element can be expressed as small whole numbers.
- In this case, the mass ratio of nitrogen in hydrazine to nitrogen in ammonia is 28 g to 14 g, which simplifies to 2:1. This indicates that for every fixed mass of nitrogen in ammonia, there is a corresponding fixed mass of nitrogen in hydrazine that maintains a simple ratio.

6. **Conclusion**:
- The relationship illustrated by the mass of nitrogen in hydrazine being one and a half times that in ammonia exemplifies the law of multiple proportions.

### Final Answer:
The fact illustrates the **Law of Multiple Proportions**.