Answer:
To compare the covalency and electronic cloud expansion (B) of the complexes [Rh(en)3]3+ and [Rh(H2O)6]3+, we can use the Jørgensen approximation. In this approximation, the parameter B is given by the formula:
B = (h × K) / n
Where:
h is the nephelauxetic parameter for the ligand,
K is the metal-specific constant for the metal ion, and
n is the coordination number.
Given that K for Rh(III) is 0.30, h for (en) is 1.29, and h for H2O is 1.0, we can calculate B for each complex:
For [Rh(en)3]3+:
Coordination number (n) = 3 (since there are 3 ethylenediamine ligands).
B = (1.29 × 0.30) / 3 = 0.129
For [Rh(H2O)6]3+:
Coordination number (n) = 6 (since there are 6 water ligands).
B = (1.0 × 0.30) / 6 = 0.05
Comparing the B values, we find that [Rh(en)3]3+ has a higher B value (0.129) than [Rh(H2O)6]3+ (0.05). A higher B value indicates a more covalent character and greater electronic cloud expansion. Therefore, [Rh(en)3]3+ is more covalent and has more electronic cloud expansion than [Rh(H2O)6]3+.
Step-by-step explanation: