The nature of oxides $V_{2}O_{3}$ and $CrO$ is indexed as '$X$' and '$Y$' type respectively. The correct set of $X$ and $Y$ is:

Iron exhibits $+2$ and $+3$ oxidation states. Which of the following statements is incorrect for iron?

Describe the chemical reactions of the lanthanoids with $H_2$ and $O_2$.

Which of the following statements are correct?
$A$. The $M^{3+}/M^{2+}$ reduction potential for iron is greater than manganese.
$B$. The higher oxidation states of first row $d$-block elements get stabilized by oxide ion.
$C$. Aqueous solution of $Cr^{2+}$ can liberate hydrogen from dilute acid.
$D$. Magnetic moment of $V^{2+}$ is observed between $4.4-5.2 \ BM$.
Choose the correct answer from the options given below:

Concentrated sodium hydroxide can separate a mixture of

How would you account for the increasing oxidising power in the series $VO_2^+ < Cr_2O_7^{2-} < MnO_4^-$?