The percentage of hydrogen in water and hydrogen peroxide is 11 .1 and 5.9 respectively . These figures illustrate

Options

A. Law of multiple proportions
B. Law of conservation of mass
C. Law of constant proportions
D. Law of combining volumes

Answer

To solve the question regarding the percentage of hydrogen in water (H2O) and hydrogen peroxide (H2O2), we need to analyze the data provided and relate it to the laws of chemistry.

### Step-by-Step Solution:

1. **Identify the Compounds**:
- We have two compounds: water (H2O) and hydrogen peroxide (H2O2).
- The percentage of hydrogen in water is given as 11.1%.
- The percentage of hydrogen in hydrogen peroxide is given as 5.9%.

2. **Calculate the Mass of Hydrogen in Each Compound**:
- For water (H2O):
- Molar mass of H2O = (2 × 1) + (16) = 18 g/mol
- Percentage of hydrogen = (mass of hydrogen / molar mass of H2O) × 100
- Mass of hydrogen in H2O = (2 g / 18 g) × 100 = 11.1%

- For hydrogen peroxide (H2O2):
- Molar mass of H2O2 = (2 × 1) + (2 × 16) = 34 g/mol
- Percentage of hydrogen = (mass of hydrogen / molar mass of H2O2) × 100
- Mass of hydrogen in H2O2 = (2 g / 34 g) × 100 = 5.9%

3. **Compare the Percentages**:
- The percentage of hydrogen in water is significantly higher than in hydrogen peroxide.
- Specifically, the percentage of hydrogen in water (11.1%) is approximately double that of hydrogen peroxide (5.9%).

4. **Relate to 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 in small whole numbers.
- Here, hydrogen is combining with oxygen in two different compounds (H2O and H2O2), and the ratios of the percentages of hydrogen can be interpreted as being in a whole number ratio.

5. **Conclusion**:
- Since the percentages of hydrogen in these two compounds illustrate the principle that hydrogen can combine with oxygen in different ratios, we conclude that the figures illustrate the **Law of Multiple Proportions**.

### Final Answer:
The figures illustrate the **Law of Multiple Proportions** (Option A).