Help with chemistry lab!

Mar 2019
We did a chemistry lab and have some questions after to submit and I’m really stuck and baffled one a few of them so I’d really appreciate some help and guidance.

5.Is the 2-nitrobenzaldehyde used in this experiment an example of an ortho or para substituted benzene molecule? What does this mean? Why is it important with respect to this experiment?

17. What is the structure of indigo?

16. Describe how indigo dye is fast, and show the leuco and leucoindigo reduction and oxidation process.

25. Cotton fibers are composed of the cellulose polymer (Figure 1.c). Explain why indigo adheres to the cotton fabric so effectively, describing the intermolecular forces involved.

19. Give the common name and draw the structure of another example of an organic dye and state a use for organic dyes other than for colouring fabrics
May 2015
New Delhi -India
Most of the answers you can search yourself on internet and if something is not clear then we can discuss here.
Apr 2019
Yes, chemtopper is correct. That being said, I love the chemistry of dyes, and their long convoluted history. Especially of indigo. My aunt even colors her hair with indigo leaf powder! It has been used in certain parts of the world for millennia to color beads, clothes, royal robes, ceramics, tattoos etc. Although its just a bush which grows easily in suitable conditions, the economic value is quite high. Every time I wear my jeans, I think of the chemistry textbook(Chemistry: An Atoms First Approach), which first got me all excited about by 'blue' jeans and thereon the chemistry of indigo and other dyes. I sometimes think science taught with its relevance in our world is a more exciting way to learn the subject, rather than follow a textbook approach. I think a good teacher can help us engage really well with a subject.
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