Tag: chemistry

Questions Related to chemistry

Single $N-N$ bond is weaker than the single $P-P$ bond. This is because of:

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. larger $N-N$ bond length in comparison to $P-P$ bond length

  2. high interelectronic repulsion of the non-bonding electrons, owing to the small $N-N$ bond length in comparison to that in $P-P$ single bond

  3. higher electronegativity of $N$ in comparison to $P$

  4. smaller atomic size of $N$ as compared to that of $P$

Show answer
Correct Option: B,D
Explanation:

$N-N$ single bond is weaker than $P-P$ bond due to smaller size of $N$ as compared to $P$. Smaller size of $N$ leads to smaller $N-N$ bond length. As a result, the lone pair of electrons on the both the $N$ atoms repel each other leading to unstability or weakening of $N-N$ bond. Because of larger size of $P$ atom, $P-P$ bond length is more and lone pair-lone pair repulsion between $P$ atoms is less which makes the $P-P$ bond stronger than $N-N$ bond.

Alkali metals dissolve in liquid ammonia and produces _______.

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. deep blue solution

  2. a solution which are conducting in nature

  3. red coloured solution

  4. Both $1$ and $2$

Show answer
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 :

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. Bleaching agent

  2. Antisepics

  3. Restoring colour of old paintings

  4. Rocket Propellant

Show answer
Correct Option: D

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

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. smaller $N-N$ bond energy

  2. larger $N-N$ bond energy

  3. low inoziation enthalpy

  4. none of these

Show answer
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?

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. $NCl _3$

  2. $NI _3$

  3. $NBr _3$

  4. $NF _3$

Show answer
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:

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. acidic

  2. basic

  3. neutral

  4. none of the above

Show answer
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?

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. $NCl _3$

  2. $NBr _3$

  3. $NI _3$

  4. $NF _3$

Show answer
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:

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. liquid form

  2. gaseous form

  3. mixture of liquid and gases

  4. none

Show answer
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:

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. $NO _2$

  2. $N _2O _4$

  3. $NO$

  4. $N _2O _3$

Show answer
Correct Option: C
Explanation:

$N _2+O _2 \rightarrow NO$

The reaction occurs at temperature greater than 2000 C. 

Nitrogen can combine with:

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. only metals

  2. only non-metals

  3. both metals and non-metals

  4. neither metals nor non-metals

Show answer
Correct Option: C
Explanation:

Nitrogen can combine with both metals and non metals.

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