Interstitial Compounds

Q. why hcl predominantly covalent in gaseous state but is ionic in gaseous solution give explanation

Q. Which of the following is/are true about interstitial compounds:

1. Interstitial compounds have the same chemical properties as that of the parent metal.
2. Interstitial compounds have the same physical properties as that of the parent metal.
3. As a result of filling up of interstitial spaces, these compounds becomes rigid and hard.
4. Interstitial compounds have higher melting points which are higher than those of pure metals.

Q. Which of the following lanthanoid ions is diamagnetic?

1. $Sm{}^{2+}$

2. $Ce{}^{2+}$

3. $Yb{}^{2+}$

4. $Eu{}^{2+}$

Q. The compound $ZnF{e}_2{O}_4$ is

1. A normal spinel compound

2. Interstitial compound

3. Covalent compound

4. Co-ordination compound