Tag: p- block elements-ii

Questions Related to p- block elements-ii

Alkali metals dissolve in liquid ammonia and produces _______.

  1. deep blue solution

  2. a solution which are conducting in nature

  3. red coloured solution

  4. Both $1$ and $2$


Correct Option: D
Explanation:

Alkali metal when reacts with liquid ammonia reaction is given by,


$ M +(x+y) NH _3\rightarrow M^+(NH _3)x + e^{-}(NH _3) _y$

 this electrons is free and gives very good conductivity as well blue colour.

$N _{2}H _{4}+2H _{2}O _{4}\rightarrow 4H _{2}O _2$. 


This equation suggests the use of $H _{2}O _{2}$ as :

  1. Bleaching agent

  2. Antisepics

  3. Restoring colour of old paintings

  4. Rocket Propellant


Correct Option: D

$CN^-$ and $N _2$ are isoelectronic. But in contrast to $CN^-, N _2$ is chemically inert because of:

  1. smaller $N-N$ bond energy

  2. larger $N-N$ bond energy

  3. low inoziation enthalpy

  4. none of these


Correct Option: B
Explanation:

Both $CN^-$ and $N _2$ have the same number of electrons but $N _2$ is more stable and chemically inert. This is because $N _2$ has a very high bond energy because of the presence of a triple bond between the two $N$ atoms. Both atoms in $N _2$ have achieved a stable electronic configuration, making the $N _2$ atom highly stable. $CN^-$ also has a triple bond but the bond is polar, unlike $N _2$ in which there is no bond polarity. Therefore, $CN^-$ is less stable and not chemically inert.

Which of the following halide of nitrogen is not explosive in nature?

  1. $NCl _3$

  2. $NI _3$

  3. $NBr _3$

  4. $NF _3$


Correct Option: D
Explanation:

The only stable halide of nitrogen $NF _3$ is not explosive. The other halides are explosive due to their unstable nature because of much larger sizes.


Hence, the correct option is $D$

Hydride of nitrogen is:

  1. acidic

  2. basic

  3. neutral

  4. none of the above


Correct Option: B
Explanation:

Hydride of nitrogen is basic due to lone pair of electrons on nitrogen atom. The common hydrides of nitrogen are hydrazine,diazene,ammonia out of which only ammonia is thermally stable.

Which of the following halide of nitrogen is unstable in nature?

  1. $NCl _3$

  2. $NBr _3$

  3. $NI _3$

  4. $NF _3$


Correct Option: A,B,C
Explanation:

Nitrogen has very small size as compared to the halogens, which have much larger sizes. Due to this, they can not remain bonded to the nitrogen atom and hence are highly unstable. $NF _3 $ is stable because fluorine and nitrogen have comparable sizes and electronegativity.

In the commercial preparation of dinitrogen by the liquefaction and fractional distillation,dinitrogen is obtained in:

  1. liquid form

  2. gaseous form

  3. mixture of liquid and gases

  4. none


Correct Option: B
Explanation:

In the commercial preparation of dinitrogen by the liquefaction and fractional distillation,dinitrogen is obtained in gaseous form.

Compound formed on reaction of nitrogen with oxygen at very high temperature is:

  1. $NO _2$

  2. $N _2O _4$

  3. $NO$

  4. $N _2O _3$


Correct Option: C
Explanation:

$N _2+O _2 \rightarrow NO$

The reaction occurs at temperature greater than 2000 C. 

Nitrogen can combine with:

  1. only metals

  2. only non-metals

  3. both metals and non-metals

  4. neither metals nor non-metals


Correct Option: C
Explanation:

Nitrogen can combine with both metals and non metals.

$N _2+3H _2 \rightarrow NH _3$
$N _2+Li \rightarrow 2Li _3N$

Which of the following is a part of the catalyst system used in Haber's process?

  1. Copper oxide

  2. Iron 

  3. Potassium oxide

  4. Aluminium oxide


Correct Option: B,C,D