To determine whether each compound is ionic or molecular, we need to analyze their characteristics based on the descriptions given:
### Compound 1:
- Description: Compound 1 is described as a hard grayish-white solid. A small 250 mg sample of it is put into a quartz tube and heated strongly. It starts to melt at 1055°C.
- Analysis: The description of Compound 1 presents both ionic and molecular properties, making it difficult to definitively classify. Generally, ionic compounds exhibit high melting points and are hard solids, but some molecular compounds can also exhibit high melting points and be hard. Due to the ambiguity, it is not possible to clearly determine the type based on the given information.
- Conclusion: It is not possible to decide if Compound 1 is ionic or molecular based on the provided description.
- Classification: Can't decide
### Compound 2:
- Description: Compound 2 is a dull white smooth solid which does not conduct electricity. Applying an ordinary laboratory burner to the material makes the substance hot, but it does not otherwise change. The substance cannot be melted or even softened by any ordinary laboratory equipment.
- Analysis: This description suggests that the compound is very stable and does not conduct electricity, which is typically associated with molecular solids (such as polymers or network covalent solids like diamond). However, certain ionic compounds (like some metal oxides or salts) can also exhibit similar properties. This makes it challenging to classify definitively.
- Conclusion: It is not possible to decide if Compound 2 is ionic or molecular based on the provided description.
- Classification: Can't decide
### Compound 3:
- Description: Compound 3 is a clear liquid with a strong smell. If heated gently, it boils at 115°C.
- Analysis: The description of Compound 3 strongly suggests that it is a molecular compound. Molecular compounds are often liquids or gases at room temperature, have relatively low boiling points (compared to ionic compounds), and can have discernible odors due to volatile organic compounds.
- Conclusion: Compound 3 can be classified as molecular based on its liquid state, distinct smell, and boiling point.
- Classification: Molecular
### Summary
1. Compound 1: Can't decide
2. Compound 2: Can't decide
3. Compound 3: Molecular
