Embibe Experts Solutions for Chapter: The d- and f-Block Elements, Exercise 2: Exercise-2

In the following reaction

$\mathrm{xZn}+{\mathrm{yHNO}}_3\left(\mathrm{dil}\right)\to \mathrm{aZn}{\left({\mathrm{NO}}_3\right)}_2+{\mathrm{bH}}_2\mathrm{O}+{\mathrm{CNH}}_4{\mathrm{NO}}_3$
What is the sum of the coefficients $(\mathrm{a}+\mathrm{b}+\mathrm{c})$?

Of the ions ${\mathrm{Zn}}^{2+}, {\mathrm{Ni}}^{2+}$ and ${\mathrm{Cr}}^{3+}$,
(Atomic number of $\mathrm{Zn}=30, \mathrm{Ni}=28 \text{and} \mathrm{Cr}=24$)

Which of the following group of ions is paramagnetic in nature:

The colour of the transition metal ions is/are due to:

Which of the following statements are correct when a mixture of $\mathrm{NaCl}$ and ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ is gently warmed with concentrated ${\mathrm{H}}_2{\mathrm{SO}}_4$?

Which of the following statement(s) is/are correct?

Pyrolusite is ${\mathrm{MnO}}_2$ used to prepare ${\mathrm{KMnO}}_4$, ${\mathrm{MnO}}_2\stackrel{\mathrm{I}}{⟶}{\mathrm{MnO}}_2^{2-}\stackrel{\mathrm{II}}{\to }{\mathrm{MnO}}_4^{-}$.

Steps $\mathrm{I}$ and $\mathrm{II}$ are respectively:

Which of the following statements are correct?