$\underbrace {\mathop {Hg{I_2}\,}\limits_{'X'} \xrightarrow[{Sublimation}]{\Delta }\,\mathop {Hg{I_2}}\limits_{'Y'} \xrightarrow{{Cooling}}\mathop {Hg{I_2}}\limits_{'Z'} }_{On\,\,rubbing}$
$'X'$ $→$ Yellow, $'Y'$ $→$ Red, $'Z'$ $→$ Yellow
$'X'$ $→$ Red, $'Y'$ $→$ Yellow, $'Z'$ $→$ Red
$'X'$ $→$ Red, $'Y'$ $→$ Yellow, $'Z'$ $→$ Yellow
$'X'$ $→$ Yellow, $'Y'$ $→ $ Red, $'Z'$ $→$ Red
Assertion : Transition metals are good catalysts.
Reason : $V_2O_5$ or $Pt$ is used in the preparation of $H_2SO_4$ by contact process.
A pink colored salt on dry heating becomes blue in colour. Salt may contain
The oxoanion in which the oxidation state of the central atom is same as its group number in the periodic table is
Effective magnetic moment of $S{c^{ + 3}}$ ion is
Which one of the following statements shows the correct percentage of carbon in steel, pig iron and wrought iron