The compound [PtCl2P(C2H5)3]2 can exhibit geometrical isomerism because it contains a square planar coordination geometry around the platinum atom. In this compound, the two ethyl groups (C2H5) can be arranged either cis or trans to each other. This results in two different isomers with distinct spatial arrangements. The other compounds listed do not have the necessary structural features to exhibit geometrical isomerism.

he correct answer is 1.15 Ǻ. In Fe(CO)5, the CO bond length will be slightly longer than the CO bond length in carbon monoxide alone. This is because the presence of the iron atom in Fe(CO)5 can slightly weaken the CO bond, causing it to stretch and increase in length. Therefore, the CO bond length in Fe(CO)5 is slightly longer than 1.128 Ǻ, but not as long as 1.72 Ǻ or 1.118 Ǻ. The closest option is 1.15 Ǻ, which is the correct answer.

The given structure represents a carbonyl compound, with CO groups attached to a central metal atom Co. The number of CO groups on each side of the metal atom is represented by the value of n. In this case, the structure shows that there are 4 CO groups on each side of the metal atom, resulting in a value of n equal to 4.

Diamagnetic substances are those that do not have any unpaired electrons and are not attracted to a magnetic field. In octahedral complexes, strong field ligands cause pairing of electrons in the d-orbitals, resulting in all electrons being paired and making the complex diamagnetic. Therefore, Co3+ in an octahedral complex with a strong field ligand is diamagnetic.

An octahedral complex refers to a coordination compound with six ligands surrounding the central metal ion, forming an octahedral shape. In the given options, the d8 (high spin) configuration is the only one that can form an octahedral complex. This is because d8 refers to a metal ion with eight d-electrons, which allows for the formation of six coordination bonds with ligands. The high spin configuration indicates that the electrons will occupy the available d-orbitals in a way that maximizes their spin, resulting in a high spin complex. Therefore, d8 (high spin) is the correct answer.