Iodine is formed when potassium iodide reacts with a solution of

Match the following:

List-$I$	List-$II$
$A$. $Co^{2+}$	$I$. Yellow colour
$B$. $Fe^{2+}$	$II$. Dark green colour
$C$. $Ni^{2+}$	$III$. Blue colour
$D$. $Cu^{2+}$	$IV$. Pale green colour
	$V$. Pink colour

The correct answer is

The color of acidified $K_2Cr_2O_7$ is not changed by:

Which one of the following statements is correct when $SO_2$ is passed through acidified $K_2Cr_2O_7$ solution?

The number of terminal oxygen atoms present in the product $B$ obtained from the following reaction is $....$
$4FeCr_2O_4 + 8Na_2CO_3 + 7O_2 \rightarrow 8Na_2CrO_4 + 2Fe_2O_3 + 8CO_2$
$2Na_2CrO_4 + 2H^{+} \rightarrow B + H_2O + 2Na^{+}$

Which of the following statements is true for $Fe_3O_4$?