The general electronic configuration of the transition elements is
(n-1)d10, (n+1)s2
(n- 1)d1-10, (n + 1)s1-2
(n- 1)d1-10, np6,ns2
(n- 1)d1-10, ns1-2
Select the coloured compound amongst the following .
(At. no. Ti= 22, Cr= 24, Cu= 29, Zn= 30)
TiCl4
CrCl3
ZnCl3
CuCl
B.
CrCl3
22Ti = [Ar] 3d2 4s2 Ti4+ = [Ar]
(No unpaired electron)
34Cr = [Ar] 3d5 4s1 Cr3+= (Ar] 3d3
(Three unpaired electrons)
30Zn =[Ar] 3d10 4s2 Zn = [An] 3d10
(All electrons paired)
29Zn =[Ar] 3d10 4s2 Zn+ = [An] 3d10
(All electrons paired)
Since, Cr3+ ion has 3 unpaired electrons, therefore its salt, i.e., CrCl3 will be coloured.