Go To Index
Chapter No.5
d- Block Elements
Scientific Reasons
Q.1: Why most of the transition elements and their compounds are paramagnetic?
Ans: Most of the transition elements have their unpaired electron in d-orbital causing paramagnetic property i.e. attracted by the magnetic fields like Sc, V, Ti, Cr, Mn etc.
Q.2: Why H2O and NH3 act as ligand but H3O+ and NH4+ do not?
Ans: H2O and NH3 have lone pair of electrons donating to central atom and act as ligand, but H3O+ and NH4+ do not have any lone pair of electrons to form coordinate covalent bond.
Q.3: Why electronic configuration of Cr is 4s1, 3d5 instead of 4s2, 3d4, while that of Cu is 4s1, 3d10 instead of 4s2, 3d9?
Ans. In Cr and Cu one electron from 4s orbital jumps to 3rd orbital in order to gain the extra stability of lower energy orbital and single spin electron.
Hence Cr has configuration of ls2, 2s2, 2p6,3s2,3p6, 4s1 , 3d5
and copper has ls2, 2s2, 2p6,3s2,3p6, 4s1, 3d10.
No comments:
Post a Comment