Copper sulfate why is it blue

The forum is a one-room schoolhouse with some readers 3rd-graders, and some post-docs, so it's sometimes hard to know what depth students require and can understand :- Regards,. Can You Solve My Problem? Why Does This Change Occur? Why does the colour of copper sulfate solution change from blue to white when you dehydrate the crystal? I've been studying this in year 12 chemistry at the moment and it's due to its emission spectra.

Energy from light and other outside sources is absorbed which can then bump electrons to a shell of higher energy level. When the electrons fall back to their original shell due to not having enough energy to orbit the nucleus in that shell they must release some energy and they do so by giving off light, in the case of copper ions the amount of energy given off produces blue light.

Hence the colour that's how they spell color in Australia where I'm from of the copper solutions. In the case of dehydrated copper sulfate there are no copper ions free, the copper is ionically bonded to the sulfate. Light reflects off of things, but some colors reflect more than others.

Which colors reflect the best has to do with the material. We usually just memorize this -- oranges are orange, apples are red. But the "why" question is not all that easy to answer. It has to do with the atoms that make up the material, and how they are arranged among themselves.

Copper is indeed red-ish by itself, and sulfur is yellow, by itself. But when combined, their atoms work together to form an overall compound, copper sulfate.

This compound is different from the atoms that formed it. It is blue. It does not conduct electricity very well copper does The electrons which circle the copper atom interact with the light in a way to make copper color. Same with sulfur. But when the compound is formed, then the electrons do not circle just one single copper, but work their way around the copper, the sulfur, some oxygen atoms etc etc.

The electrons see a bigger picture, and interact with incoming light in a different way. We see this as a color change.

You can actually watch a chemical reaction take place -- mix two things together, each of which has no color, and watch some colored liquid form. In dehydrated copper sulphate there are no copper ions free, the copper is ionically bonded to the sulphate. Why the copper is blue in color? This is the question given to me on which I am having seminar I should explain it for minutes in front of all.

Hi Akansha. I'm afraid your lecture on this topic will be excruciating for you and the listeners if you don't put effort into it. Please read the page, ask a followup question, and engage us in a practice run for your lecture :- Alternately, look up "black body radiation", study it a bit, and I'm betting you'll deliver a fascinating minutes! Good luck, and Regards,. The oxidation state refers to how many electrons an atom has gained or lost compared to its neutral state.

With one or two or three electrons missing the available energy states empty electron shells are different and the electron energy transition jumping to a lower energy state and emitting a photon of a specific wavelength that is the primary contributor to the observable color will be different.

Thanks Ray. It may be beyond Akansha's pay grade, I know it's beyond mine, but this funny business about the color of glowing metals is what forced Max Planck, completely against his will and contrary to his sense of logic, to drag the whole damn world into the wacky age of quantum mechanics :- Regards,.

Why mercury subchloride and mercuric perchloride are white in color and red sulphate of mercury in red color, but these three compounds are derived from mercury? Hi Suganya. Please try your best to detail what you understood and didn't understand from the previous discussion so we can keep moving forward. A deep blue copper sulphate solution turns pale blue when water is added.

Name and describe the phenomenon which causes the change in colour from deep blue to pale blue. Sorry, Loreal, but I can't get my brain going 'til I've had a proper morning coffee, and I think my wife made the pot with 1 scoop of ground coffee instead of 6. It tastes like dishwater and looks very pale from dilution as well. I'll be back after I make a fresh pot of strong, deep black, coffee :- Regards,.

This is because of the Jahn-Teller effect, because the electrons crowd each other. Hi Lorial The amount of light that passes through a solution the colour you see depend upon the concentration of the solution.

It has nine electrons in its outermost energy level or shell; these so-called valence electrons all occupy 3d orbitals.

The water molecules and sulfate ions are attracted to the positive charge on the copper ion, so they approach it and arrange around it in an octahedral configuration. Ultimately, then, two of the five 3d orbitals have increased energy; these are called the eg orbitals. The other three, by contrast, have decreased energy and are called the t2g orbitals.

A photon of light will be absorbed by the coordination complex if it has an energy equivalent to the difference between the state an electron now occupies and the energy of another state available to it. Consequently, the copper sulfate complex can absorb photons of light with energies equivalent to the difference in energy between t2g and eg orbitals.

As it happens, the difference in energy for the copper sulfate complex is equivalent to the difference in energy for photons of light in the red-orange region of the spectrum. Since reddish light is absorbed while blue light is transmitted, the copper sulfate appears blue. When the copper sulfate dissolves in water, the copper and sulfate ions dissociate.

Now the copper ion forms an octahedral complex where it's surrounded by six molecules of water. The effect is still very much the same, however, because the split between t2g orbitals and eg orbitals in this new complex is still such that reddish-orange light is absorbed and you see a blue-colored solution.

Based in San Diego, John Brennan has been writing about science and the environment since How to Find the Lattice Energy of a Compound. How to Calculate the First Ionization Energy of the What Is Light Measured In? How to Calculate the Energy of Photons. How to Calculate Bond Order.