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 :

The octahedral diamagnetic low spin complex among the following is :

Using column chromatography, mixture of two compounds 'A' and 'B' was separated. 'A' eluted first, this indicates 'B' has

Given below are two reactions, involved in the commercial production of dihydrogen (H$$_2$$). The two reactions are carried out at temperature "T$$_1$$" and "T$$_2$$", respectively

$$C(s) + {H_2}O(g)\buildrel {{T_1}} \over \longrightarrow CO(g) + {H_2}(g)$$

$$CO(g) + {H_2}O(g)\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{Catalyst}^{{T_2}}} C{O_2}(g) + {H_2}(g)$$

The temperatures T$$_1$$ and T$$_2$$ are correctly related as :