Given below are two statements: Statement (I): A solution of Ni H 2 O 6 2 + is green in colour. Statement (II): A solution of Ni ( CN ) 4 2 - is colourless. In the light of the above statements, choose the most appropriate answer from the options given below:

Step-by-step solution

In Ni H 2 O 6 2 + , H 2 O is a weak field ligand. Therefore, there are unpaired electrons in Ni 2 + . In this complex, the d electrons from the lower energy level can be excited to the higher energy level i.e., the possibility of d - d transition is present. Hence, Ni H 2 O 6 2 + is coloured. In Ni CN 4 2 - , the electrons are all paired as CN - is a strong field ligand. Therefore, d - d transition is not possible in Ni CN 4 2 - . Hence, it is colourless. Ni H 2 O 6 + 2 → Green colour solution due to d - d transiti