each unit of copper (II) sulfate? Please show me your work!
There is a explanation to this in the Crystal Field Theory of complex salts which explains the colour to many substances including CuSO4. It states that the d-orbitals of the Cu(+2) ions are of the same energy level when they are left alone in void. However when you supply a ligand - like water, these energy levels develop a small difference. Now electrons in the level that has a lesser amount of energy can absorb a certain wavelength of light photons and get excited to the next level, momentarily. When they return, they re-emit that photon, giving colour that you see. So when you remove the water by heating, it is back to its original self with all the d-orbitals at the same level. So you miss the colour.
Copper (11) sulphate is CuSO4.xH2O MW is 62.5 + 32+ 64 + 18x = 95.14 + 18x If it is 25.5% Cu then 62.5/(95.14 + 18x) = 25.5/100 rearranging then 62.5/0.255 = 95.14 +18x = 245 18 x = 245-95.14 = 149.96 x = 149.95/18 =8.3
