When XO₂ is fused with an alkali metal hydroxide in presence of an oxidizing agent such as KNO₃ ; a dark green product is formed which disproportioates in acidic solution to afforda dark purple solution. X is :

Which of the following complexes will shows geometrical isomerism ?

Which of the following conversions involves change in both shape and hybridisation ?

In Wilkinson's catalyst, the hybridization of central metal ion and its shape are respectively :