InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
`NCl_(3)` is an endothermic compound while `NF_(3)` is an exothermic compound. |
|
Answer» Due to smaller size of F as compared to Cl, the N-F bond is much stronger `(272k kJ mol^(-1))` than N-Cl bond `(201 kJ mol^(-1))` while bond dissociation energy of `F_(2)(158.8 kJ mol^(-1))` is much lower than that of `Cl_(2)(242.6 kJ mol^(-1))`. Therefore, energy released during the formation of `NF_(3)` molecule is more than the energy needed to break `N_(2)(941.4 kJ mol^(-1))` and `F_(2)` molecules into individual atoms. In other words formation of `NF_(3)` is an exothermic reaction or `NF_(3)` is an exothermic compoud. `{:(N_(2)(g)+3F_(2)(g)to2NF_(3)(g),,DeltaH=-214.2Jmol^(-)),(N_(2)(g)+3Cl_(2)(g)to2NCl_(3)(g),,DeltaH=-463.2kJmol^(-1)):}` In contrast, energy released during the formation of `NCl_(3)` molecule is les than the energy needed to break `N_(2)andCl_(2)` molecules into individual atoms. In other words, formation of `NCl_(3)` is an endothermic reaction or `NCl_(3)` is an endothermic compound. |
|