All $Cu(II)$ halides are known,except the iodide. The reason for this is that:

The compound $AgF_2$ is an unstable compound. However,if formed,the compound acts as a very strong oxidizing agent. Why?

Given below are two statements for catalytic properties of transition metals. Statement $I$: First row transition metals which act as catalyst utilise their $3d$ electrons only for formation of bonds between reactant molecules and atoms on the surface of catalyst. Statement $II$: There is increase in the concentration of reactants on the surface of catalyst which strengthens the bonds in reacting molecules. In the light of the above statements,choose the correct answer from the options given below:

Assertion : $PbI_4, BiCl_5, FeI_3, CuI_2$ do not exist. Reason : Higher oxidation states of metal ions are strong oxidising agents which give redox reactions with the iodide ion.

What is the general molecular formula of the products obtained on heating lanthanoids $(Ln)$ with sulphur?

Which of the following oxidation states of manganese exhibits the most powerful oxidizing property?