In manufacture of sodium carbonate from Solvay (or ammonia-soda) process the raw material used is :

(1) $\mathrm{NaOH}$                                             

(2) ${\mathrm{Na}}_2{\mathrm{SO}}_4$

(3) $\mathrm{NaCl}$                                               

(4) ${\mathrm{NaHCO}}_3$

Which of the following reactions of potassium superoxide supply oxygen gas in the breathing equipments used in space and submarines?

(1) Reaction of superoxide with nitrogen in the exhaled air.

(2) Reaction of superoxide with moisture in the exhaled air.

(3) Reaction of superoxide with carbon dioxide in the exhaled air

(1) (1), (2) and (3)                                       

(2) (2) and (3) only

(3) (2) only                                                 

(4) (1) and (2) only

Which of the following acts as an oxidizing as well as a reducing agent?

(1) ${\mathrm{Na}}_2\mathrm{O}$                                     

(2) ${\mathrm{NaO}}_3$

(3) $\mathrm{NaNO}$                                     

(4) ${\mathrm{NaNO}}_2$

Alkaline earth metal nitrates on heating decompose to give:

(1) $\mathrm{M}{\left({\mathrm{NO}}_2\right)}_2 \mathrm{and} {\mathrm{O}}_2 \mathrm{only}$                                   

(2) $\mathrm{MO}, {\mathrm{N}}_2 \mathrm{and} {\mathrm{O}}_2$

(3) $\mathrm{MO}, {\mathrm{NO}}_2 \mathrm{and} {\mathrm{O}}_2$                                         

(4) $\mathrm{MO} \mathrm{and} {\mathrm{NO}}_2 \mathrm{only}$

Consider the following statements and pick out the correct one.

(1) The solubility, thermal stability, and the basic character of the hydroxides of alkaline earth

      metals increases from $\mathrm{Mg}{\left(\mathrm{OH}\right)}_2 \mathrm{to} \mathrm{Ba}{\left(\mathrm{OH}\right)}_2.$

(2) The dehydration of hydrated chlorides, bromides, bromides and iodides of Ca, Sr and Ba can be

      achieved on heating.

(3) The chlorides of both beryllium and aluminium are soluble in organic solvents and are strong

      Lewis acids.

(1) (1) and (2) only                                     

(2) (1) and (3) only

(3) (1), (2) and (3)                                     

(4) none

A metal [X] heating on nitrogen gas gives [Y]. [Y] on treatment with ${\mathrm{H}}_2\mathrm{O}$ gives a colourless gas which when passed through ${\mathrm{CuSO}}_4$ solution gives a blue colour. [Y] is-

1. $\mathrm{Mg}{\left({\mathrm{NO}}_3\right)}_2$                                     

2. ${\mathrm{Mg}}_3{\mathrm{N}}_2$

3. ${\mathrm{NaN}}_3$                                             

4. $\mathrm{MgO}$

Assertion : Beryllium resembles aluminium.

Reason : : Charge / radius of $B{e}^{2+}$ ion is nearly the same as that of the $A{l}^{3+}$ ion.

Assertion : As the electropositive character increases down the group, the stability of carbonates and hydrogen carbonates of alkali metals increases.

Reason : Lithium carbonates is not so stable to heat ; lithium being very small in size polarizes a large $C{O}_3^{2-}$ion leading to the formation of more stable $L{i}_{2}O$ and $C{O}_2$.

The following is the correct order of chemical reactivity with water according to electrochemical series-

1. K>Mg>Cu>Zn                                     

2. K>Mg>Zn>Cu

3. Cu>Zn>K>Mg                                     

4. Mg>K>Cu>Zn

In the reaction $\mathrm{M}+{\mathrm{O}}_2\to {\mathrm{MO}}_2$ (superoxide) the metal is -

1. Li                 

2. Na

3. K                 

4. Ba