Potassium permanaganate and chromic acid can both be used as classification tests for alcohols. methanol and two amino acids are the hydrolysis products of aspartame. Why is potassium permanganate a better choice as a classification test reagent than chromic acid to detect the methanol produced by aspartame hydrolysis?

This is because if its visible accurate colour change.

Explanation:

Potassium Permanganate(KMNO4)is a water soluble salt which loses its purple color as it oxidizes alcohols. This makes it easier for the reaction to be followed visually.

Chromic acid(H2CrO4) on the other hand is an acid which oxidizes amino acids. It however tends to give a false positive color change. This makes Potassium permanganate preferable.

grav potential energy

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.