What are the oxidation states of phosphorus in the following:

(i) H₃PO₃ (ii) PCl₃ (iii) Ca₃P₂ (iv) Na₃PO₄ (v) POF₃?

How can you prepare Cl₂ from HCl and HCl from Cl₂? Write reactions only.

What inspired N. Bartlett for carrying out the reaction between Xe and PtF₆?

Write balanced equations for the following:

(i) NaCl is heated with sulphuric acid in the presence of MnO₂.

(ii) Chlorine gas is passed into a solution of NaI in water.

How are xenon fluorides XeF₂, XeF₄ and XeF₆ obtained?