`Sc^+3` ions are colourless. Why ?

[Sc(H_2O_6)_6]^(3+) and [Ti(H_2O)_6]^(3+) ions are coloured why ?

Which of the following ions are colourless ?

Which of the following ions are colourless ?

Sc^(3+) ion is colourless while Cr^(3+) Ion is coloured. Explain.

Name two tripositive lanthanoid ions which are colourless.

Ions of Zn^(2+) and Ti^(4+) are colourless while Cu^(2+) and Ni^(2+) are coloured . Why ?

Explain Co^(2+) is coloured whereas Ti^(4+) is colourless. Why ?

Addition of chlorine to potassium iodide solution gives it a brown colour but excess of chlorine turns it colourless. Why?

CuSO_4 .5H_2O is blue in colour while CuSO_4 is colourless. Why ?

CuSO_4 .5H_2O is blue in colour while CuSO_4 is colourless. Why ?