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1answer
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Good Fabric-Friendly Solvent for Aluminium Chlorohydrate

I have recently found out that the white/yellowish "sweat" stains one occasionally finds on t-shirts might be aluminium chlorohydrate polymers. While talk about aluminium and antiperspirants is all ...
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2answers
48 views

How are electrons in conjugated molecules excited? [duplicate]

I have recently started reading about colour in organic molecules and come across conjugation of pi bonds. My question is pretty short... In transition metal ions I understand colour is caused by ...
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1answer
45 views

Why is $\ce Co(SCN)_4$ blue?

Why is $\ce Co(SCN)_4$ blue? I simply can't predict the colors of such inorganic salts. I have learnt that $\ce {Co^{2+}}$ salts are pink in color. Also, if the ligand is a strong field ligand ...
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1answer
52 views

Does Nitrogen dioxide change colour if we put it in a constant temperature of e.g. 100 kelvin?

The changing of the colour of $\ce{NO2}$ is because of a change in temperature, resp. heating and cooling?
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1answer
67 views
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3answers
429 views

what is the origin of the colour of azo dyes?

what is the origin of the colour of azo-dyes? Is it the same reason as to why transition metal complexes have colour?
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3answers
107 views

How do i find out which species is colourless? [closed]

Among the following $$\ce{TiF6^{2-},\ CoF6^{3-},\ NiCl4^{2-},\ CuCl2}$$ how do i find the species which i colorless If possible please provide the concept used to deduce the result it will be very ...
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2answers
105 views

Why does ZnO turn yellow when it is hot?

Why does ZnO's color become yellow when it is hot? I have read that it is because of physical properties, but I need a more elaborate explanation.
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1answer
181 views

Can I synthesize iron acetate like this?

The oxidation state of the iron doesn't matter too much; I am just trying to make an attractive red-brown ink. Here are some instructions I prescribed to a friend. Here's an approximately decent ...
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0answers
52 views

Which Dispersing Agent is common and best for dispersing of $\ce{TiO2}$ pigments in produce of gouache?

I'm a mathematician who know nothing from chemistry. Even I don't know I should ask it here or another place. Below is a question of one of my friends. Please help me find him. Which Dispersing Agent ...
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0answers
73 views

What reaction took place?

Okay, so I was fiddling about in the chemistry lab, and I added: Sodium Nitroprusside (soln) $\small\ce{ Na_2[Fe(CN)_5NO] }$ with Potassium Ferrocyanide (soln) $\small\ce{ K_4[Fe(CN)_6] }$. ...
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3answers
116 views

Can you colour a flame, and what would the effects be?

I read this question : Flame temperature for cooking food and was thinking, could companies colour there flames so that products would heat quicker? how would they do this, also could you use this to ...
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2answers
125 views

Egg-Detection in Pastries: An Analysis in Heat-Alterated Molecule Identification

I would like to know if anybody here knows of a method to detect the presence of ovalbumin--or any unique, egg-related molecule, in a baked good. Here I am anticipating that the "unique egg-related ...
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1answer
97 views

How Does The Mordant, Ferric Acetate, Interact With Tannins When Ebonizing Wood?

Ferric Acetate (II) and (III) are "mordants," which intensify wood staining in direct proportion to the tannin concentration in the wood. Some wood stainers add tea to increase the tannin content and ...
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2answers
4k views

Why do transition elements make colored compounds?

Why do transition metals element make colored compound both in solid form and in solution? Is it related with their electrons or something else?
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1answer
81 views

Is it possible to calculate chromacity coordinates using absorbance values?

I have absorbance values for blood plasma. Absorbance was measured in range of 380 – 600 nm every 5 nm ending up with absorbance values for 45 wave lengths. I was browsing through literature, and I ...
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0answers
56 views

What causes Copper Rose?

We made a solution of Tetrakis Copper(I) hexafluorophosphate and the usual color is yellowish. As it oxidizes to Cu(II), it should turn blue. However, our current mixture has an off color that is ...
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2answers
4k views

Why are some salt solutions coloured?

I notice that salt solutions of $\ce{NaCl}$ and $\ce{KCl}$ are colourless while those of $\ce{CuSO4}$ and $\ce{FeSO4}$ are coloured. I got as far as figuring that it has to do with the transition ...
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2answers
169 views

What chemical compounds were used in CRT phosphors?

In the old days computer monitors and televisions were built from cathode ray tubes (CRTs) where the image was generated by an electron beam hitting phosphors which emitted light approximating the ...
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1answer
76 views

Question about fire and colors

Most solids objects turn black after they are burnt. But some turn white. Why is that ?
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3answers
860 views

How may copper acetate ligands be manipulated to change colors?

I have a solution of copper acetate and I would like to play around with the ligands to get different colors. Background: The copper acetate was made through mixing vinegar (5% acetic acid), NaCl, ...
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2answers
643 views

Color of chromate and permanganate

I've heard quite a few times that the chromate and permanganate have a $d^3s$ configuration. Also, their colors arise due to a rapid switching of electrons between the oxygen and metal atoms. I don't ...