Question

Which of the following statements about the interstitial compounds is incorrect ?

• A. They have higher melting points than the pure metal
• B. They retain metallic conductivity
• C. They are chemically reactive
• D. They are much harder than the pure metal

Answer 1

The Correct Option is C

To determine which of the given statements about interstitial compounds is incorrect, let's first understand what interstitial compounds are:

Interstitial Compounds: These are compounds formed when small atoms (like hydrogen, carbon, or nitrogen) are trapped in the interstitial spaces (gaps) of metal lattices. These compounds have unique characteristics due to the nature of their formation.

Now let's evaluate each statement provided in the options:

1. They have higher melting points than the pure metal: This statement is generally true. Interstitial compounds tend to have higher melting points compared to their parent metals because the small atoms occupy spaces in the metal lattice, strengthening the metallic bond.
2. They retain metallic conductivity: This is also true. Even with interstitial atoms, the metallic structure is largely retained, allowing them to conduct electricity like the parent metals.
3. They are chemically reactive: This statement is incorrect. Interstitial compounds are typically less reactive chemically as the metallic lattice is strengthened and stabilized by the presence of the interstitial atoms, reducing the compound's overall chemical reactivity.
4. They are much harder than the pure metal: True. The inclusion of small atoms in the lattice structure increases hardness, as the movement of metal atoms within the lattice is restricted.

Conclusion: Based on the definitions and properties of interstitial compounds, it is clear that the incorrect statement is "They are chemically reactive." Interstitial compounds are generally quite stable, which makes them less chemically reactive compared to their pure metal forms.