Alkaline earth metal nitrates on heating decompose to give:

(1) $\mathrm{M}{\left({\mathrm{NO}}_2\right)}_2<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{O}}_2<mspace\; width="1em"></mspace>\mathrm{only}$                                   

(2) $\mathrm{MO},<mspace\; width="1em"></mspace>{\mathrm{N}}_2<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{O}}_2$

(3) $\mathrm{MO},<mspace\; width="1em"></mspace>{\mathrm{NO}}_2<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{O}}_2$                                         

(4) $\mathrm{MO}<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{NO}}_2<mspace\; width="1em"></mspace>\mathrm{only}$

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 $\mathrm{Mg}{\left(\mathrm{OH}\right)}_2<mspace\; width="1em"></mspace>\mathrm{to}<mspace\; width="1em"></mspace>\mathrm{Ba}{\left(\mathrm{OH}\right)}_2.$

(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 

The reaction of sodium with water is highly exothermic. The rate of reaction can be lowered by-

(1) Decreasing the temperature 

(2) Mixing with alcohol

(3) Mixing with acetic acid 

(4) Making an amalgam

Sodium reacts with water less vigorously than potassium because-

1. It has a higher atomic weight.

2. It is less electropositive .

3. It is more electronegative. 

4. It is a metal .

The correct relation about the density of Na and K is 

1. Na > K                                                     

2. Na = K

3. K > Na                                                     

4. Li > K