The figure below shows the fluorescence emission spectra of 2-naphthol at pH2 and pH 13. Wavelength (nm) (i) Draw the structure of 2-naphthol at each pH. [4 marks] (ii) Calculate the energy of the photons emitted at the approximate lambda max of both spectra and the difference in energy between these maxima. (h=6.626176 1034 joule-seconds.) [6 marks] (iii) Explain with the aid of a diagram why the change in pH affects the emission spectra of 2-naphthol. [8 marks] (iv) Calculate the quantum yield of fluorescence under acidic conditions for 2naphthol given the experimental life time (f) and radiative life time (0) are 6.94 ns and 38.5 ns respectively. Comment on the quantum yield with reference to the rate coefficient of fluorescence (kf) and rate coefficient of non-radiative processes (knr)