Question

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

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

Answer 1

The Correct Option is B

To determine the incorrect statement about interstitial compounds, let's analyze the given options based on the properties of interstitial compounds:

1. They retain metallic conductivity: Interstitial compounds typically contain small nonmetal atoms (like hydrogen, boron, carbon, or nitrogen) embedded in the crystal lattice of metals. These compounds maintain the metallic nature of metals, including their conductivity, because the lattice structure remains largely unaffected by the small atoms occupying the interstitial spaces.
2. They are chemically reactive: Interstitial compounds, such as metal carbides and nitrides, tend to be less reactive due to the stable bonding between the metal and nonmetal atoms. Their strong covalent nature generally imparts high stability to these compounds, making them less chemically reactive compared to other forms of the elements.
3. They are much harder than the pure metal: The presence of small atoms in the interstitial sites strengthens the metal, often making these compounds significantly harder than the pure metal itself. This is a well-known property, especially for carbides and nitrides.
4. They have higher melting points than the pure metal: Interstitial compounds often have higher melting points than the pure metal due to the strong covalent bonds formed between the small nonmetal atoms and the metallic lattice.

Based on the analysis, the incorrect statement about interstitial compounds is the one that claims they are chemically reactive. Therefore, the correct answer is:

They are chemically reactive.