Why do –NH2 and –NR2 and –OH change colour of a chromophore?

Axis of a UV-visible spectrum

Axis of an IR spectrum

Why are there many shades of blue?

As size of conjugated system increases

Principles of green chemistry

How would you analyse the fatty acids in a triester?

What additional info is obtained by adding a mass spectrometer to a g.l.c. instrument?