Dalton's atomic theory fails to explain.........law of combining volumes

Answer

To solve the question regarding Dalton's atomic theory and its limitations, particularly in relation to the law of combining volumes, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Dalton's Atomic Theory**:
- Dalton's atomic theory, proposed in the early 19th century, states that matter is made up of indivisible atoms, and these atoms combine in fixed ratios to form compounds.

2. **Identify the Laws of Chemical Combination**:
- Dalton's theory explains several laws of chemical combination, including:
- **Law of Constant Composition**: A given compound always contains the same proportion of elements by mass.
- **Law of Multiple Proportions**: 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 are in simple whole numbers.

3. **Recognize the Law of Combining Volumes**:
- The law of combining volumes, formulated by Joseph Louis Gay-Lussac, states that when gases react together at constant temperature and pressure, the volumes of the reacting gases and the volumes of the products (if gaseous) are in simple ratios.

4. **Identify the Limitation of Dalton's Theory**:
- Dalton's atomic theory does not adequately explain the behavior of gases and their volumes during reactions. It primarily focuses on solid compounds and does not account for the gaseous state and the relationships between their volumes.

5. **Conclusion**:
- Therefore, the blank in the statement "Dalton's atomic theory fails to explain ________" can be filled with "Gay-Lussac's law of combining volumes".

### Final Answer:
Dalton's atomic theory fails to explain **Gay-Lussac's law of combining volumes**.

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