On heating $Mn(OH)_2$ with $PbO_2$ and conc. $HNO_3$,a pink colour is obtained due to the formation of:

Which one of the following ions participates in the production of $ATP$ from the oxidation of glucose?

When a mixture of $NaCl$,$K_{2}Cr_{2}O_{7}$ and conc. $H_{2}SO_{4}$ is heated in a dry test tube,a red vapour $(X)$ is evolved. This vapour $(X)$ turns an aqueous solution of $NaOH$ yellow due to the formation of $Y$. $X$ and $Y$,respectively,are

Compounds of $d-$block elements can stabilize in higher oxidation states only with $F$ and $O$. Which statement is incorrect?

What is the oxidation state of osmium in $7B$ and $7C$,respectively?

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