How would you account for the following: (i) NF3 is an exothermic compounds but NCl3 is not.
How would you account for the following:
(i) NF3 is an exothermic compounds but NCl3 is not.
(ii) The acidic strength of compounds increases in the order:
PH3 < H2S < HCl
(iii) SF6 is kinetically inert.
1 Answers
(i) This is because bond dissociation energy of F2 is lower than Cl2 Moreover, fluorine forms stronger bond with nitrogen due to comparable size.
(ii) The acidic strength of compounds increases because of increase in polarity of E—H bond from P—H to H—Cl, which is due to increase in electronegativity of E.
(iii) In SF6, S atom is sterically protected by six F atoms and does not allow water molecules to attack the S atom. Further, F does not have d-orbitals to accept the electrons denoted by H2O molecules. Due to these reasons, SF6 is kinetically an inert substance.