Light and Colors
Question:

COLORS ARE AROUND US EVERYWHERE... 

We can see colors as a result of the interaction between light and matter. Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum. The word usually refers to visible light, which is visible to the human eye and is responsible for the sense of sight. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), between the infrared (with longer wavelengths) and the ultraviolet (with shorter wavelengths). The main source of light on Earth is the Sun. We can see also the visible colors of the light by rainbow which is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky.

Take a look into the attached video for more information about light and its interaction with matter to obtain colors, then answer the following question below.

 BLOSSOMS lesson: https://blossoms.mit.edu/videos/lessons/why_are_sky_blue_and_leaves_green

Could  the compound p-amino-o-Cresol be used as a hair dye?

 

5 People tried to answer this question

Yes. The chemical structure of the compound contains three double bonds which gives it the ability to absorb all the wavelengths of the white light except the red one.

Yes. The compound is stable and it is liquid at room temperature. It will react with sun light to give red color thus it could be used as hair dye.

No. The compound has to be reacted with other chemical reagents in order to get a product which has multiple conjugated double bonds.

No. The chemical structure of the compound does notcontain metal ions which gives it the ability to absorb all the wavelengths of the white light except the red one.

Very Good :-)

The compound p-amino-o-Cresol alone contributes little in the way of color. It has to be reacted with p-aminophenols in the presence of H2O2 by coupling reaction to produce dye molecules. The dye molecules contain multiple conjugated double bonds system, which give them the ability to absorb some wavelengths of light at the visible region of the spectrum more than others (TYPE A interaction, between light and matter). By this way, we can produce the desired end strong color. 

Press here to get more examples of hair dyes

Try again :-(

Although the chemical structure of p-amino-o-Cresol contains benzene ring with 3 double bonds, it can not be used alone as a dye hair. It has a weak color.

Try again :-(

Although the chemical structure of p-amino-o-Cresol contains benzene ring with 3 double bonds, it can not be used alone as a dye hair. It has a weak color. 

In addition, the compound is solid at room temperature due to hydrogen bond interactions between the molecules.

 

Try again :-(

There are organic (carbon compounds), inorganic (such as minerals) and organometallic compounds that absorb light at the visible region due to their unique chemical structure.  



Comments:
1.  ibrahim rami (15.06.2017 am 12.39.17)
Light and Colors-feedback

Hello

I would like to thank you for the interesting Challenge you gave in this question.

The scientific background and the animation are clear and understandable.

I think that your question is between understanding to applying level.

Some comments and recommendations:

1)      To give some information about pigments and what is p-amino-o-Cresol.

2)      To give more detailed feedback for the wrong answer.

3)      The answers are very closed and need a deep knowledge in chemistry

And Because of my lack of knowledge I tried to learn about p-amino-o-Cresol in the internet and I find this information: "6-Amino-m-Cresol, 6-Amino-o-Cresol… are crystals that range in color from beige and reddish-brown to brown. These ingredients are used in the formulation of semi-permanent and permanent hair dyes, colors, and tints " (see site http://www.cosmeticsinfo.org/ingredient/amino-cresol-hair-dye-ingredients), the right answer you gave is " No, The compound has to be reacted with other chemical reagents in order to get a product which has multiple conjugated double bonds"- please check that.

 

Thanks again

Rami

2.  ibraheem najwan (02.07.2017 pm 10.47.53)
light and colors

Dear amona,

I realy enjoyed reading your question it's really an interesting subject, and the video was  clear and simple,I learned alot of new information. but still because I am not from the chemestry field it was hard for me to understand few things like what is the p-amino-o- cresol , so I couldn't answer the question  correctly.
I think you should explain more and give mor information about basics, couse its really high level question that needs more knowledge in chemestry which is good.

Thanks
Najwan Ibraheem



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