Indigo is the blue dye used in jeans. Leucoindigo is a yellow water soluble dye that dyes cotton. Once the cotton is dyed with leucoindigo it is exposed to air which oxidezes the leucoindigo to blue water insoluble indigo.

a) Draw in the hydrogen and lone pairs where needed in indigo.

b) How many atoms in indigo have a tetrahedral shape? How many atoms in indigo have a trigonal pyramid shape?

c) Circle the functional groups in indigo. Write the name of the functional group next to your circle.

d) Draw an absorption spectrum of leucoindigo. What color is absorbed by leucoindigo? Draw a simple energy level diagram of leucoindigo. Calculate the energy difference between energy levels.

e) Identify the chemical forces between leucoindigo and cotton.

f) Leucoindigo is soluble in water but indigo is not. Give reasons.