The correct option is
C P-3 Q-1 R-4 S-2
P.
[Cr(NH3)4Cl2]Cl is Tetraamminedichlorochromium (III) Chloride.
Charge present on each ion is Cl=−1, Cr=x, NH3=0.
Since chloride is outside the complex and it has a negative charge. So, the complex gets +1 charge.
Now, the addition of each ion inside = charge of overall complex
x−2=1⇒x=3
Cr=Z=24; Electronic Configuration = 3d54s1
Cr3+=3d3
Therefore, hybridisation is d2sp3 and as there is no pairing of electron, it is left with 3 unpaired electrons.
So, it is paramagnetic. Also, it exhibits cis-trans isomerism (geometrical) as it is a octahedral complex of the form MA4B2
Q. [Ti(H2O)5Cl](NO3)2
Ti has an electronic configuration of [Ar]3d24s2.
Thus, it has unpaired electrons, hence it is paramagnetic.
Also, here the counter ion, i.e., NO3 can also act as a ligand. Hence, it also shows ionisation isomerism.
R. [Pt(en)(NH3)Cl]NO3
Pt has an electronic configuration of [Xe]4f145d96s1
It does not have any unpaired electrons, hence it is diamagnetic.
Also, here the counter ion, i.e., NO3 can also act as a ligand. Hence, it also shows ionisation isomerism.
S. [Co(NH3)4(NO3)2]NO3
Co has electronic configuration [Ar]3d74s2
It does not have any unpaired electrons, hence it is diamagnetic.
Also, it also shows cis-trans isomerism.