Saved Bookmarks
| 1. |
The first ionisation enthalpies of S, Cl and Ar are 1000, 1256 and 1520 kJ/mol-1, respectively. Explain the observed trend. |
|
Answer» (i) The atomic number increases as, 16S < 17Cl < 18Ar1. (ii) Due to decrease in atomic size and increase in effective nuclear charge, Cl binds valence electrons strongly. (iii) Hence ionisation enthalpy of Cl (1256 kJ mol-1) is higher than that of S(1000 kJ mol-1) (iv) Ar has electronic configuration 3s23p6. Since all electrons are paired and the octet is complete, it has the highest ionisation enthalpy, (1520 kJ mol-1) |
|