Tag: p- block elements-ii

Questions Related to p- block elements-ii

A translucent white waxy solid (A) reacts with excess of chlorine to give a yellowish white powder (B). (B) reacts with organic compounds containing -OH group converting them into chloro derivatives. (B) on hydrolysis gives (C) and is finally converted to phosphoric acid. (A), (B) and (C) are?

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. $P _{4}$,$PCl _{3}$,$H _{3}PO _{4}$

  2. $P _{4}$,$PCl _{5}$,$H _{3}PO _{3}$

  3. $P _{4}$,$PCl _{5}$,$POCl _{3}$

  4. $P _{4}$,$PCl _{3}$,$POCl _{3}$

Show answer
Correct Option: C
Explanation:

A translucent white waxy solid (A) reacts with excess of chlorine to give a yellowish white powder (B). Here B is $PCl _5$.$PCl _5$ reacts with organic compounds containing -OH group converting them into chloro derivative $POCl _3. $.$PCl _5$ on hydrolysis gives (C).C is $POCl _3$ and is finally $POCl _3$ converted to phosphoric acid.

So  (A), (B) and (C) are $P _{4}$,$PCl _{5}$,$POCl _{3}$.

Hence option C is correct.

$\mathrm{P}\mathrm{Cl} _{3}$ is prepared by the action of $\mathrm{Cl} _{2}$ on :

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. $ \mathrm{P} _{2}\mathrm{O} _{3}$

  2. $ \mathrm{P} _{2}\mathrm{O} _{5}$

  3. White $\mathrm{P}$

  4. $\mathrm{H} _{3}\mathrm{P}\mathrm{O} _{3}$

Show answer
Correct Option: C
Explanation:

White P is reactive due to strain.
$P _{4}+6Cl _{2}\ \to \ 4PCl _{3}$
(White P)

Which of the following exist as dimer :

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. NO

  2. $NO _{2}$

  3. $P _{2}O _{3}$

  4. All

Show answer
Correct Option: D
Explanation:

All have dimer forms

$NO$ as $N _{2}O _{2}$

$NO _{2}$ as $N _{2}O _{4}$

$P _{2}O _{3}$ as $P _{4}O _{6}$

What is the oxidation state of Phosphorus in ${P}{Cl} _{3}$?

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. ${+}{5}$

  2. ${+}{3}$

  3. ${+}{1}$

  4. ${-}{3}$

Show answer
Correct Option: B
Explanation:

The oxidation state of ${P}$ in ${P}{Cl} _{3}$ is ${+3}$.
Each Chlorine atom has an oxidation number of ${-1}$. There are three chlorine atoms, hence the total oxidation number of the Chloride ions in ${-3}$. ${PCl} _{3}$ molecule is neutral. Hence the oxidation number of Phosphorus should be ${+3}$

What is the boiling point of ${PCl} _{3}$?

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. ${-93.6}^{o}$ ${C}$

  2. ${169}^{o}$ ${C}$

  3. ${100}^{o}$ ${C}$

  4. ${76.1}^{o}$ ${C}$

Show answer
Correct Option: D
Explanation:

The boiling point of ${PCl} _{3}$ is ${76.1}^{o}$ ${C}$

What is the hybridization of Phosphorus Trichloride?

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. ${sp}^{3}$

  2. ${sp}^{2}$

  3. ${sp}$

  4. None of these

Show answer
Correct Option: A
Explanation:

The hybridization of ${PCl} _{3}$ is ${sp}^{3}$. Phosphorus has five electrons in its outermost shell. Thus it forms three sigma bonds with three neighbouring Chlorine atoms. The remaining two electrons remain as a lone pair on Phosphorus atom. Thus these three sigma bonds and one lone pair, make this molecule ${sp}^{3}$ hybridized.

What kind of a molecule is ${P}{Cl} _{3}$?

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. Ionic

  2. Polar covalent

  3. Non polar covalent

  4. none of these

Show answer
Correct Option: B
Explanation:

$PCl _3$ is a polar covalent molecule. It is polar because chlorine atoms are more electronegative than phosphorus atom and hence the polartity of the molecule is towards Chlorine atoms.
It is covalent because, Phosphorus has ive electrons in its outermost shell. It requires three more to complete its octet. Each chlorine atom has seven electrons in their outermost shell, they all require one electron each to complete their octet. Thus both phosphorus and chlorine complete their octet by mutually sharing their electrons. Hence this molecule is polar covalent in nature.

What is produced as an impurity during the production of ${PCl} _{3}$:

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. ${PCl} _{5}$

  2. ${POCl} _{3}$

  3. ${PSCl} _{3}$

  4. ${Cl} _{2}$

Show answer
Correct Option: A
Explanation:

During the indusrial preparation of ${PCl} _{3}$, ${PCl} _{5}$ or Phosphorus Pentachloride is produced as an impurity. The balanced equation can be written as-
${PCl} _{3}$ ${+}$ ${Cl} _{2}$ ${=}$ ${PCl} _{5}$
Thus this impurity formation can be stopped by continual removal of ${PCl} _{3}$ as it is formed.

Phosphorus trichloride, $PCl _3$, undergoes hydrolysis to produce an oxoacid. The formula of oxoacid is :

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. $HPO _3$

  2. $H _3PO _3$

  3. $H _3PO _4$

  4. $H _3PO _2$

Show answer
Correct Option: B
Explanation:

$PCl _3$ on hydrolysis gives $HCl$ and $H _3PO _3$.

The reaction is:

$PCl _3 + 3H _2O \rightarrow H _3PO _3 + 3HCl$

Aqueous solution of PBr$ _{3}$ conducts electricity due to the presence of:

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. $\mathrm{HOBr}$

  2. $\mathrm{HBr}$

  3. $\mathrm{H} _{3}\mathrm{P}\mathrm{O} _{4}$

  4. $\mathrm{H} _{2}\mathrm{O}$

Show answer
Correct Option: C
Explanation:

$PBr _{3}+3H _{2}O\ \to \ H _{3}PO _{4}+HBr$
HBr is covalent $H _{3}PO _{4}$ is ionic. Solution conducts electricity due to ions.
So aqueous solution of $PBr _{3}$ conducts electricity due to presence of $H _{3}PO _{4}$.