Comments on: Conjugation And Color (+ How Bleach Works)

By: Prof Aloir A. Merlo

Prof Aloir A. Merlo — Fri, 24 Nov 2023 16:12:01 +0000

To answer your comment I would like to remmember you that in electrophic addition in alkenes the slow step of mechanism is the addition of electrophile. In the bleach, HOCl decompose to OH- and Cl+. bcose of this the base (OH-) do not attack the poliene before the addition of electrophile C+
Please feel free to be in touched to clarified your doubts

By: James Ashenhurst

James Ashenhurst — Thu, 05 Sep 2019 17:49:37 +0000

In reply to a. Put in a link. Thank you! Try blowing up the images.

By: James Ashenhurst

James Ashenhurst — Sat, 27 Apr 2019 03:21:45 +0000

In reply to Janette. I don't know that you'd end up with white leaves. You'd certainly eliminate the colors from chlorophyll and the carotenoids, but those aren't the only pigments in leaves. The most likely event to my mind is that you'd end up with brown leaves.

By: Janette

Janette — Fri, 30 Mar 2018 14:37:37 +0000

Hi! Your post is very interesting and I think I can use the info here for my art project. I’m planning to make flowers out of leaves. The goal is to remove all the colors from the leaves but not get a skeleton-like effect. The leaves will be all-white and ready for dyeing. I’m thinking of of using clorox and hydrogen peroxide since they are readily available, unlike other chemicals which would need special govt permission for me to buy here in my country. Are clorox and peroxide enough? I would greatly appreciate your help because this project is very important to me since it can potentially generate livelihood for the less fortunate people in my place. Thank you!

By: a

Fri, 26 May 2017 05:47:06 +0000

> But it will have to wait until the next post for a full treatment.

no link to next / prev posts

tiny font in the diagram texts; cannot read

By: James

James — Wed, 28 Sep 2016 18:41:13 +0000

In reply to Christine. Hi Christine - in bleach, the two sides of the molecule have different behaviours. The electrophilic and oxidizing part is the Cl. Bleach can act as a base (although this is less likely) through the hydroxide functionality, i.e. the terminal O(-).

By: Christine

Christine — Tue, 20 Sep 2016 03:31:21 +0000

I’m still confused about bleach. Here, we are saying that the chlorine is electrophilic, which makes perfect sense…and generally, we say that bleach is a strong oxidant, again suggesting that it will be accepting electrons.
But we also generally say that bleach is a strong base. And by that definition, it should be donating electrons…this is my confusion. How can it be a base and an oxidizing agent at the same time, when the definitions are seemingly opposite?

By: James

James — Thu, 15 Sep 2016 19:37:27 +0000

In reply to John A Spevacek. Thanks John, as always. Good point about the dispersion. I never think about the polymer angles. I delegate that to you!

By: Singh

Singh — Tue, 13 Sep 2016 19:10:40 +0000

It is so nostalgic to re-learn the long-forgotten things! Keep up your good work :)

By: John A Spevacek

John A Spevacek — Fri, 09 Sep 2016 15:09:44 +0000

The latex rubber example is a little bit of apples and oranges. The white color is common for any latex/emulsion and it arise from the physical structure of the dispersion – the emulsion particles scatter all light. A better comparison would be a dried latex, but they are typically light yellow due to impurities.

But this got me thinking: what would happen if you dispersed any of the conjugated molecules from above in an emulsion. Would the whiteness from the scattering dominate the absorption of the conjugation? I bet it would, but I really don’t know.