A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution is added to the aformentioned solution, a white precipitate is obtained which does not dissolve in dil. nitric acid. The anion is :

Xenon hexafluoride on partial hydrolysis produces compounds 'X' and 'Y' . Compounds 'X' and 'Y' and the oxidation state of Xe are respectively :

XeF₆ on partial hydrolysis with water produces a compound ‘X’. The same compound ‘X’ is formed when XeF₆ reacts with silica. The compound ‘X’ is :

The number of P−OH bonds and the oxidation state of phosphorus atom in pyrophosphoric acid (H₄P₂O₇) respectively are :