The green colour produced in the borax bead test of a chromium$(III)$ salt is due to formation of . . . . . . :

Match Column $A$ with Column $B$:

Column $A$	Column $B$
$(1)$ Brass	$(a)$ $Ni$ $(60\%)$,$Cr$ $(40\%)$
$(2)$ Bronze	$(b)$ $Cu$ $(80\%)$,$Sn$ $(20\%)$
$(3)$ Cupronickel	$(c)$ $Cu$ $(90\%)$,$Sn$ $(10\%)$
$(4)$ Nichrome	$(d)$ $Cu$ $(70\%)$,$Zn$ $(30\%)$
	$(e)$ $Cu$ $(75-85\%)$,$Ni$ $(15-25\%)$

The most basic hydroxide among the following is

Correct statements from the following are:
$A$. Potassium dichromate is an oxidising agent and it oxidises $FeSO_4$ to $Fe_2(SO_4)_3$ in acidic medium.
$B$. Sodium dichromate can be used as primary standard in volumetric estimation.
$C$. $CrO_4^{2-}$ and $Cr_2O_7^{2-}$ are interconvertible in aqueous solution by varying the $pH$ of the solution.
$D$. $Cr-O-Cr$ bond angle in $Cr_2O_7^{2-}$ is $126^\circ$.
Choose the correct answer from the options given below:

Match the following:

List-$I$ (Aquated Ion)	List-$II$ (Colour)
$A. Ni^{2+}$	$I. \text{Violet}$
$B. Fe^{3+}$	$II. \text{Blue}$
$C. Mn^{3+}$	$III. \text{Yellow}$
$D. V^{4+}$	$IV. \text{Red}$
	$V. \text{Green}$

Which transition metal compound is used in a dry battery cell?