$CrO_3$ is a/an ...

$X$ is an oxoanion of the lightest element of group $7$ in the periodic table. The metal is in $+6$ oxidation state in $X$. The color of the potassium salt of $X$ is

$Orange-(A)$ (Inorganic compound) $+ H^{+} + H_2O_2 \to Blue-(B)$. The oxidation state of the central atom in compound $(B)$ is:

One of the important uses of ferrous sulphate is in the

Iron on reacting with carbon gives:

$A$ compound of mercury used in cosmetics,in Ayurvedic and Yunani medicines and known as vermilion is