Question

Why Para nitrophenol shows red shift in alkaline medium

Answer 1

Answer:

P-nitrophenol shows a red shift in an alkaline medium because of a phenomenon called Bathochromic shift.

Bathochromic shift refers to the change in the spectral band position of p-nitrophenol with respect to its reflectance, absorption, transmittance, or the emission spectra of the molecule to longer wavelengths of low frequency.

Red color is present in the visible spectrum and has a longer wavelength compared to other colors, this phenomenon is called the red shift.

In an alkaline medium, p-nitrophenol shows red shift since the negatively charged oxygen molecules delocalise effectively compared to the unshared electron pair.