The UV-visible spectrum of [Ni(en)\(_3\)]\(^{2+}\) (en = ethylenediamine) shows absorbance maxima at 11200 cm\(^{-1}\), 18350 cm\(^{-1}\), and 29000 cm\(^{-1}\).

[Given: Atomic number of Ni = 28] The correct match(es) between absorbance maximum and electronic transition is/are

This corresponds to options (A), (B), and (D).
An aqueous solution of Co(ClO4)2·6H2O is light pink in colour. Addition of conc. HCl results in an intense blue coloured solution due to the formation of a new species. The new species among the following is:

[Given: Atomic number of Co = 27]
In the 1H-NMR spectrum of the following molecule, the signal of proton Ha appears as:

The Vaska’s complex trans-IrCl(CO)(PPh3)2 shows a band at 1967 cm−1 for the \( \nu_{\text{CO}} \) stretching vibration in its infrared spectrum. The complex(es) that will show an increase in the \( \nu_{\text{CO}} \) stretching vibration from 1967 cm−1 is/are:
The 1H NMR spectrum of the given iridium complex at room temperature gave a single signal at 2.6 ppm, and its 31P NMR spectrum gave a single signal at 23.0 ppm. When the spectra were recorded at lower temperatures, both these signals split into a complex pattern. The intra-molecular dynamic processes shown by this molecule are:

what is the final product
intensity ratio of final product