R.R. Mishra Solutions for Exercise 4: QUESTIONS ON HIGHER ORDER THINKING SKILLS (HOTS)

Select from $\mathrm{ZnS}$, ${\mathrm{CaCO}}_3$, $\mathrm{Na}$, $\mathrm{Fe}$, $\mathrm{Ti}$with the correct descriptions below.

It is easily cut by a knife and burns in contact with moist air.

Select from $\mathrm{ZnS}$, ${\mathrm{CaCO}}_3$, $\mathrm{Na}$, $\mathrm{Fe}$, $\mathrm{Ti}$with the correct descriptions below.

 It is concentrated by froth floatation process.

Select from $\mathrm{A}) \mathrm{ZnS}, \mathrm{B}) {\mathrm{CaCO}}_3, \mathrm{C}) \mathrm{Na}, \mathrm{D}) \mathrm{Fe}, \mathrm{E}) \mathrm{Ti}$ with the correct descriptions below.

Calcination is employed to change it into metal oxide. (Enter your correct answer as $\mathrm{A}, \mathrm{B}, \mathrm{C}, \mathrm{D} \mathrm{or} \mathrm{E}$)

Select from $\mathrm{ZnS}$, ${\mathrm{CaCO}}_3$, $\mathrm{Na}$, $\mathrm{Fe}$, $\mathrm{Ti}$ with the correct descriptions below.

• It is called strategic element.

Select from $\mathrm{ZnS}$, ${\mathrm{CaCO}}_3$, $\mathrm{Na}$, $\mathrm{Fe}$, $\mathrm{Ti}$with the correct descriptions below.

It corrodes easily in the presence of moist air.

Three elements A, B and C undergo the following type of reactions:

$$\begin{gathered} {\mathrm{A}}_2{\mathrm{O}}_3+2\mathrm{B}\to {\mathrm{B}}_2{\mathrm{O}}_3+2\mathrm{A} \\ 3{\mathrm{CSO}}_4+2\mathrm{B}\to \hspace{0.17em}{\mathrm{B}}_2{\left({\mathrm{SO}}_4\right)}_3+3\mathrm{C} \\ 3\mathrm{CO}+2\mathrm{A}\to {\mathrm{A}}_2{\mathrm{O}}_3+3\mathrm{C} \end{gathered}$$

Which one of A, B and C is most reactive and which one is least reactive?

An element exists as a liquid under normal conditions of temperature and pressure. The density of this element is much greater than that of water. Name this element. Is it a metal or a nonmetal?

Zinc oxide reacts with acid. Therefore, it has a basic nature. Zinc oxide reacts with a base also. Therefore, it has the acidic nature. What is the correct nature of zinc oxide?