Questions tagged [color]

Questions where color (wavelengths associated with the visible region of the electromagnetic spectrum of about 400-800nm), or a color change is discussed.

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Are there any pathways that can change a solution to all colors of the rainbow?

The challenge's like this. Suppose you have a beaker containing a liquid of transparent or any color. You add some drops of another liquid and the beaker turns into, say, red after some swishing. You ...
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71 views

How to predict colour of precipitate? [duplicate]

I am currently preparing for Junior science competitions and I am coming across many questions where colour of precipitate plays important role... Like When compound $\ce{Hg2(NO3)2}$ reacts with $\ce{...
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116 views

Cobalt glass colour of potassium as

Question: Cobalt glass colour of potassium as: A) Crimson red B) Lilac C) Apple green D) Brick red I thought option B as true because on flame test, potassium gives lilac colour. But the given ...
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300 views

What is the colour of cesium?

I am confused with the color of cesium. Some websites and books say that it is a silvery white metal, and some say it has a golden colour, and some say it has a silvery golden colour. Among these ...
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273 views

What is the chemical composition of Ferrous Ferrocyanide?

To this day, iron-cyanide complexes confuses me. So, I want to settle this once and for all. After scavenging the internet, I gathered the following result: $$ \ce{Ferr} \color{blue}{\ce{ous}}~\ce{...
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Looking for gas or liquid for story research

I am working on a story for adaptation into animation. Main lead is a chemist in a traditional fantasy setting. The chemist uses her own compound to battle using fire or explosions. I love the ...
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1answer
71 views

Lithium Oxide Colour

According to Chemistry LibreText: Lithium is the lightest of all metals and is named from the Greek work for stone (lithos). It is the first member of the Alkali Metal family. It is less dense than ...
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1answer
123 views

Ferrous chloride solution coming out purple rather than green?

I've got some steel wool in hydrochloric acid to attempt to make ferrous chloride and the whole solution has turned purple. From everything I've seen it's supposed to be green. I have no idea what's ...
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99 views

Nomenclature of Colors of precipitates and solutions

I have just started learning salt analysis in inorganic chemistry. In it i came across the names of colors of various precipitates and solutions. Why do they have prefixes such as "scarlet" ...
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198 views

Comparing intensity of colour in coordination compounds

I had given an examination recently in which the question asked was: Write the decreasing order for the intensity of color in $\ce{[CoCl4]^{2-}}$, $\ce{[Co(CN)4]^2-}$, $\ce{[Co(H2O)6]^2+}$ What my ...
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1answer
117 views

Why do boron salts impart a characteristic green colour to the flame

In salts of boron it exists as a cation in the B(III) form. It is known to impart green colour in several of its salts like borates, boron triflourides, boric acid etc. If there are no electrons in ...
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How do I anodize bronze for thin film colors using electrolysis?

I am trying to change the color of the coins we have in Europe. I want to create patterns of certain colors. They are made from "nordic gold" (89% copper, 5% aluminum, 5% zinc, and 1% tin). ...
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51 views

What caused a colour change when I mixed two different dish soaps?

I recently purchased "organic" dish soap refill made from saponified coconut oil and potassium soap (full ingredient list). Instead of waiting for the old dish soap (Dawn) to be completely ...
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1answer
63 views

The color of resorcinol-formaldehyde resin

At school, I did an experiment of synthesizing resorcinol-formaldehyde resin. When I added $\ce{NaOH}$ and gave some heat, the color of resorcinol-formaldehyde resin inside the test tube became ...
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Is there a known value for the molar extinction (absorption) coefficient for amylose and amylopectin iodine complexes?

I am doing a colorimetry experiment with starch, and have a theoretical model based on Beer's law. To solve it, I need a known value for the molar extinction coefficients of amylose and amylopectin ...
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1answer
275 views

Flame Test of Alkali Metals and Alkaline Earth Metals

The flame test colors for alkali metal and alkaline earth metal salts are well known, but what about the metals themselves? Do they also give rise to the same colors (eg, brick red for Ca, pale green ...
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Why is bleaching with chlorine permanent but with sulphur dioxide temporary?

I was reading the properties of chlorine when I came across this statement: Chlorine is a powerful bleaching agent; bleaching action is due to oxidation. Chlorine bleaches vegetable or organic matter ...
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What color would be produced by the burning of the listed chemicals of the projectile weapon the carcass?

The carcass was a projectile weapon developed by the French in the second half of the 17th Century. It was "named carcass because the circles which pass from one ring, or plate, to the other, ...
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1answer
69 views

Why is my dried out copper sulphate green when wetted with water?

I dried out some blue copper sulphate in an oven to see if it would turn white which it did. I can't remember exactly but I left it overnight in the oven at around 50 C. It was white the following day....
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The colors that we see [closed]

I have a question. When I was studying Coordination Compounds, I came across this para: When a sample absorbs light, what we see is the sum of remaining colors that strikes our eyes. Observed and ...
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2answers
154 views

why do we see characteristic colors of alkali metals in oxidizing flame?

I am a high school student and I am a little confused in a topic, My confusion is that: We know alkali metals and their salts imparts characteristic color in oxidizing flame, for example: Lithium ...
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Why does my drierite turn bright bright blue, instead of pink?

Drierite a brand name of a commonly-used, calcium sulfate-based dessicant in many chemistry labs. The lab I work in has a dessicator box we use to store hygroscopic materials. It isn't a a true dry ...
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1answer
138 views

Why is HBr colorless while Br2 isn't?

Bromine ($\ce{Br2}$) has a dark reddish color. If it reacts with something like benzene, this results in the formation of Bromobenzene and $\ce{HBr}$: $$\ce{Br2 + C6H6 ->[{Cat.}]C6H5Br + HBr}$$ It ...
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1answer
465 views

Why is HgI2 a colored complex?

Why is $\ce{HgI2}$ a colored complex it has fully filled d-orbits. According to the book, one which has fully filled d-orbital has no color in transition elements. So, why is this compound colored?
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Analysis of cations using sodium thiosulphate

A question in an exam was as follows:[1] How many of the following salts are first soluble in $\ce{Na2S2O3}$ solution, followed by the formation of a white precipitate and finally the precipitate ...
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118 views

What characterises the smell of alkane hydrocarbons?

I have heard that aromatic hydrocarbons smell fruity and like petrol. However, I understand that there is a class of hydrocarbons called alkane, as for example propane or butane. I wondered if I might ...
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1answer
246 views

Why did ammonium chloride fumes turned pink in this synthesis?

I was watching the synthesis of tetrasulfur tetranitride performed by Tom on his Youtube channel, Explosion & fire. He followed the basic route: adding ammonia gas to sulfur chlorides ($\ce{SCl2}$ ...
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1answer
48 views

Actual color of colloids [closed]

I have read that the color of colloid depends upon the wavelength of light scattered by the dispersed phase and also in the sense in which the receiver receives the light. If all of this depends on ...
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1answer
105 views

Why aren't solid pure transition metals colourful?

I understand that the compounds of transition metal are colourful because of the appropriate energy gap between different d orbitals. But why aren't they also colourful in their solid pure state? For ...
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2answers
146 views

Controlled burn with colored flames (Gender Reveal) [closed]

Is there a single solvent that can dissolve chemicals/elements that when burned, will produce the color of its respective chemical/element? If so, what chemical/element can be dissolved in this ...
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2answers
348 views

The color of the most sulfides of p- and d-block elements

My teacher said that many of the sulfides of d-block and p-block are black. Why?
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1answer
111 views

What is the main contributor of the color of honey? [closed]

I was told that the color of honey contains so much chemistry and that was interesting to me and after doing a couple of research I found that the color of honey depends on the presence of plant ...
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852 views

Chemical elements or compounds with yellowish white color [closed]

Are there chemical elements or compounds that have a yellowish white (cream) color in their natural state?
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155 views

Colour due to transmission and reflection

It makes sense to me that when looking through a sample (observer | sample | light), it should appear as the opposite of the light absorbed, but it does not make sense to me to expect the same when ...
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2answers
206 views

Which is a dye: Ferric Acetate or Ferrous Acetate?

I’ve been trying to make Iron Acetate to dye leather and I cannot, for the life of me, figure this out experimentally. I’ve been allowing steel wool to react with pure white vinegar in a sealed glass ...
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70 views

Why are sulphide salts of p and d block coloured?

I have studied that sulphide salts of s block are colourless while p and d block salts are coloured. But colour intensity of a salt is directly proportional to polarisation in salt. And s block ...
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2answers
44 views

Water color additive that will maintain color when water is a thin film

I'm producing thin sheets of liquid (50 to 100 microns) from a nozzle and trying to photograph them. I think it would help if I could color the water. However, typically as water becomes more of a ...
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2answers
962 views

Titrating iodine starch solution with sodium thiosulphate - Colour change

I investigated two mixtures with different solvents, one with water and one with n-heptane. Both contained iodine $\ce{I2}$ as a solute. To both solutions I added a bit of starch. As I remember this ...
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42 views

Measuring ions through color change during electrolysis

I have very little experience in chemistry, you might consider me a physicist, and I am mostly not even sure where to find the information I need. I will start off by describing my problem, I have a ...
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213 views

Why are polynuclear carbonyl complexes coloured?

We know that polynuclear carbonyls are colored and their intensity increases with increase in metal ions. But why does the color arise? I am aware that this is due to some transition between ...
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78 views

Why are Buckminsterfullerene (C60) solutions pink/purple?

A solution of Buckminsterfullerene $\ce{(C60)}$ is shown below: According to the April 8th Wikipedia page on Buckminsterfullerene $\ce{(C60)}$: Solutions of pure C60 have a deep purple color which ...
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1answer
42 views

Can a spectrometer be used to figure out spice ratios in a sauce?

There is a really good sauce that a local restaurant makes. I have had trouble recreating it, but have gotten somewhat close. I had the following idea: I could take an "image" of the sauce's color ...
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251 views

Effect of optical isomerism on colour of transition metal complexes

I know that different stereoisomers of a given transition metal complex (cis- and trans- forms) have different colours. But do different optical isomers (non-superimposable mirror images) have ...
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Is there a way to create natural Red food coloring from Turmeric in the house kitchen?

As a non chemist I have read in the Wikipedia article Curcumin that: Curcumin becomes bright red when it interacts electrostatically with phospholipid film. This text appeared without source ...
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53 views

Looking for color changing reaction to track snow layer depth

I'm trying to find a chemical to mark the position of a snow layer with for detection in future seasons. The substance has to be: 1. Colorless 2. Not water soluble/solid 3. Stable for multiple years ...
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1answer
107 views

Some substances appear white when crushed while others do not. Why?

Calcite crystals are semi-transparent but turn white when crushed. I used to think that it has something to do with the scattering of all wavelengths of light from small particles. But that cannot be ...
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276 views

Colour of VO3^-?

To aquire the yellow colour of vanadium ion, it must be present in a 5+ oxdiation state. This can be acheived (according to my textbook) by adding dilute sulfuric acid to $\ce{NH4VO3}$, then followed ...
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1answer
281 views

Why is chromate coloured but tungstate colourless?

I have to try and work this out using the tetrahedral molecular orbital diagram for $\ce{[WO4]^2-}$ but I am confused as both are $\mathrm d^0$ right?
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1answer
2k views

Predicting colors of aqueous solutions

While going through my AP chem prep book again, I came across questions asking about the color of certain aqueous solutions. For example: Which of the following substances will produce a colorless ...
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140 views

Why does the colour of the same compound (e.g. magnesium nitride) differ?

When I am searching the colour of $\ce{Mg3N2}$ I came across photos showing different colours: greenish-yellow on Wikimedia, and some other just yellow on some Google Images results. I am eager to ...

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