Which one of the following pairs of compounds illustrate the law of multiple proportion?

Options

A. `H_(2) O, Na_(2)O`
B. `H_(2) O, H_(2) O_(2)`
C. `Na_(2) O, BaO`
D. All of these

Explanation

To determine which pair of compounds illustrates the law of multiple proportions, we first need to understand what the law states. 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.

Let’s analyze the given options step by step:

### Step 1: Understand the Law of Multiple Proportions
The law of multiple proportions applies when two elements can form more than one compound. For example, carbon and oxygen can form CO (carbon monoxide) and CO2 (carbon dioxide). The ratio of the mass of oxygen in CO to the mass of oxygen in CO2 can be expressed in whole numbers.

**Hint:** Remember that the law applies only when the compounds are formed from the same elements.

### Step 2: Analyze the First Pair: H2O and Na2O
- H2O (water) consists of hydrogen and oxygen.
- Na2O (sodium oxide) consists of sodium and oxygen.
Since these compounds contain different elements (hydrogen vs sodium), they do not illustrate the law of multiple proportions.

**Hint:** Check if both compounds contain the same elements.

### Step 3: Analyze the Second Pair: H2O and H2O2
- H2O (water) consists of 2 hydrogen atoms and 1 oxygen atom.
- H2O2 (hydrogen peroxide) consists of 2 hydrogen atoms and 2 oxygen atoms.
Here, both compounds contain the same elements (hydrogen and oxygen) and can be compared. The ratio of oxygen in H2O to H2O2 is 1:2, which is a simple whole number ratio.

**Hint:** Look for compounds that contain the same elements and compare their ratios.

### Step 4: Analyze the Third Pair: Na2O and BaO
- Na2O (sodium oxide) consists of sodium and oxygen.
- BaO (barium oxide) consists of barium and oxygen.
Again, these compounds contain different elements (sodium vs barium), so they do not illustrate the law of multiple proportions.

**Hint:** Ensure both compounds are formed from the same pair of elements.

### Conclusion
After analyzing all the pairs, we find that the only pair that illustrates the law of multiple proportions is H2O and H2O2.

**Final Answer:** The pair of compounds that illustrate the law of multiple proportions is H2O and H2O2.