Oxygen is absorbed by molten $Ag$,which is evolved on cooling and the silver particles are scattered,this phenomenon is known as

Assertion $(A)$: $CuI_2$ cannot be prepared by the reaction of $Cu^{2+}_{(aq)}$ with $I^{-}_{(aq)}$.
Reason $(R)$: Aqueous $Cu^{2+}$ solution is blue in colour.
The correct answer is:

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

Iron is rendered passive by treatment with

Which of the following is the correct order of negative values of $E^o\,M^{2+} | M$ for the elements $Cr, Mn, Fe,$ and $Co$?

How many statements are incorrect?
$(a)$ $Mn^{+3}$ and $Co^{+3}$ are strong oxidising agents.
$(b)$ $Ti^{+2}$,$V^{+2}$ and $Cr^{+2}$ are strong reducing agents.
$(c)$ $CrO_3$ is acidic in nature.
$(d)$ $E^{\circ}_{M^{+3}/M^{+2}} = -ve$ for $Fe$.