why are copper salts blue-green and zinc salts colourless?

Question

[ Cu(H2O)6 ]2+ and [ Zn (H2O)6 ]2+

Answer 1

ok the best way for you to understand this is too look at a colour cheese diagram... you'll probably find one if you look up light and spectroscopy....

basically...

copper salts are a blue green colour because they absorb light at a wavelength of between 580-630nm (the colour orange)... by looking at the colour cheese you will see that directly opposite the colour orange is the colour blue-green...

zinc salts however do not absorb light at wavelengths between 400-700nm... the human eye is only able to detect wavelength spectrums from between 400 nm to 700 nm and therefore it will appear colourless to us because we simply can't see it!

hope this helps you some, best of luck in your studies

Answer 2

Zinc Salts

Answer 3

both Copper and Zinc ae d-block elements.
the atomic number of copper is 29 and of zinc is 30. so the electronic configuration of copper wil be 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^9
and electronic configuration of zinc will be
1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10.
so the d orbital of copper is partially filled and of zinc is fully filled.
the d-block compounds are coloured b'coz they show d-d transition. but the d-d transition cannot occur if the d-orbital is empty or fully filled.
so the compounds of scandium and zinc are generally colourless.

Answer 4

copper ions have partially filled d orbitals while zinc ions have a completely filled d sublevel - one of the properties of d electrons is to produce colors when in solution - many compounds of transition elements that have unpaired d electrons have color

Answer 5

Cu2+ ions have a "hole" in the 3d sub-level, which allows some frequencies of light to be absobed. Zn2+ ions don't have this space, and so no light is absorbed.

Answer 6

just is, its natural stuff, colours happen