a) Write the chemical formulae of the following complexes:
i) Hexaammineplatinum(IV) chloride
ii) Tetraamminedichloridocobalt(III) ion
b) Using the valence bond theory of bonding in complexes, explain the geometry and magnetic nature of [Co(NH)].
i) Hexaammineplatinum(IV) chloride
ii) Tetraamminedichloridocobalt(III) ion
b) Using the valence bond theory of bonding in complexes, explain the geometry and magnetic nature of [Co(NH)].
Answer: (a)(i) [Pt(NH₃)₆]Cl₄; (ii) [Co(NH₃)₄Cl₂]⁺. (b) Co³⁺(d⁶) pairs under strong-field NH₃ → d²sp³, octahedral, diamagnetic.
Solution
(a)(i)
(ii)
(b) Co = 3d. NH (strong field) pairs the six electrons into three 3d orbitals, vacating two; these with 4s and three 4p hybridise as dsp, accepting six NH lone pairs.
Geometry: octahedral (inner-orbital).
Magnetic nature: all electrons paired → diamagnetic.
(ii)
(b) Co = 3d. NH (strong field) pairs the six electrons into three 3d orbitals, vacating two; these with 4s and three 4p hybridise as dsp, accepting six NH lone pairs.
Geometry: octahedral (inner-orbital).
Magnetic nature: all electrons paired → diamagnetic.
CBSE Class 12 Board · 2002 · Delhi; also All India Compartment · Subjective