1.0 g of an oxide of A contained 0.5 g of A. 4.0 g of another oxide of A contained 1.6 g of A . The data indicate the law of-

Options

A. (a)Reciprocal proportions
B. (b)Constant proportions
C. (c )Conservation of energy
D. (d)Multiple proportions

Answer

To solve the question, we need to analyze the given data about the oxides of element A and determine which law of chemical combination it indicates.

### Step-by-Step Solution:

1. **Identify the Mass of A in Each Oxide:**
- For the first oxide:
- Mass of A = 0.5 g
- Total mass of the oxide = 1.0 g
- For the second oxide:
- Mass of A = 1.6 g
- Total mass of the oxide = 4.0 g

2. **Calculate the Mass of Oxygen in Each Oxide:**
- For the first oxide:
- Mass of oxygen = Total mass of oxide - Mass of A
- Mass of oxygen = 1.0 g - 0.5 g = 0.5 g
- For the second oxide:
- Mass of oxygen = Total mass of oxide - Mass of A
- Mass of oxygen = 4.0 g - 1.6 g = 2.4 g

3. **Determine the Mass Ratios of A to Oxygen:**
- For the first oxide:
- Ratio of A to oxygen = Mass of A : Mass of oxygen = 0.5 g : 0.5 g = 1 : 1
- For the second oxide:
- Ratio of A to oxygen = Mass of A : Mass of oxygen = 1.6 g : 2.4 g
- To simplify this ratio, divide both sides by 0.8:
- Ratio = (1.6 / 0.8) : (2.4 / 0.8) = 2 : 3

4. **Analyze the Ratios:**
- The ratios of the masses of A to oxygen in the two oxides are 1:1 and 2:3.
- These ratios indicate that the masses of A combine with fixed masses of oxygen in simple whole number ratios.

5. **Conclude the Law:**
- The data indicates the law of multiple proportions, which states that when two elements combine to form more than one compound, the masses of one element that combine with a fixed mass of the other element are in the ratio of small whole numbers.

### Final Answer:
The data indicate the law of multiple proportions.

---