Tag: p- block elements-ii

Questions Related to p- block elements-ii

How is $ {P}{Cl} _{3} $ produced industrially?

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

  1. Reacting chlorine with white phosphorus

  2. Reacting chlorine with phosphorus acid

  3. Reacting chlorine with black phophorous

  4. All of the above

Show answer
Correct Option: A
Explanation:
Industrially Phosphorous trichloride is prepared by the reaction of Chlorine with a solution of white Phosphorous in phosphorous trichloride.
The reaction is given by:
$P _4$ $+$ $6Cl _2$ $\longrightarrow $ $4PCl _3$

What is the structure of phosphorus trichloride?

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

  1. Trigonal Pyramidal

  2. Trigonal Planar

  3. Tetrahedral

  4. Square Planar

Show answer
Correct Option: A
Explanation:

In ${ PCl } _{ 3 }$, $P$ is ${ sp }^{ 3 }$ hybridized with a lone pair. This makes its structure trigonal pyramidal. So, the correct answer is option $A$.

What is the physical state of ${PCl} _{3}$ under normal condition?

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

  1. Solid

  2. Liquid

  3. Gaseous

  4. None of these

Show answer
Correct Option: B
Explanation:

${PCl} _{3}$ is liquid under normal conditions. ${PCl} _{3}$ is a covalent compound. Phosphorus and each of the chlorine atoms fulfil their octet by mutually sharing their valence electrons. In general, covalent compounds have weak bond energy and hence they form liquid.

Dehydrated phosphorus trichloride in water gives:

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

  1. $H _3PO _3$

  2. $H _3PO _4$

  3. $H _3PO _2$

  4. none

Show answer
Correct Option: A
Explanation:

Dehydrated phosphorus trichloride in water gives phosphoric acid.

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

Hence option A is correct.

Which of the following is not correctly matched?

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

  1. $PCl _{5}$ - $sp^{3}d$ hybridisation.

  2. $PCl _{3}$ - $sp^3$ hybridisation.

  3. $PCl _{5}$ (solid) - $[PtCl _{4}]^{+}$+ $[PtCl _{6}]^{-}$.

  4. $PCl _{5}$ - brownish powder.

Show answer
Correct Option: D
Explanation:


 Colour of $PCl _5$ is not brownish but a greenish yellow crystalline solid with an irritating odour.

Hence option D is correct.

On reaction with $Cl _{2}$, phosphorus forms two types of halides 'A' and 'B'. Halide 'A' is yellowish-white powder but halide 'B' is colourless oily liquid. What would be the hydrolysis products of 'A' and 'B' respectively?

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

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

  2. $HOPO _{3}$, $H _{2}PO _{2}$

  3. $H _{3}PO _{3}$,$H _{3}PO _{4}$

  4. $HPO _{3}$,$H _{3}PO _{3}$

Show answer
Correct Option: A
Explanation:

$P+Cl _2\longrightarrow \underset {(B)}{PCl _3} +\underset {(A)}{PCl _5}$

$PCl _5+4H _2O\longrightarrow H _3PO _4+5HCl$
$PCl _3+3H _2O\longrightarrow H _3PO _3+3HCl$

In solid state $PCl _{5}$ is a :

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

  1. covalent solid

  2. octahedral structure

  3. ionic solid with $[PCl _{6}]^{+}$ octahedral and $[PCl _{4}]^{-}$ tetrahedral

  4. ionic solid with $[PCl _{4}]^{+}$ tetrahedral and $[PCl _{6}]^{-}$ octahedral

Show answer
Correct Option: D
Explanation:

In solid state $PCl _5$ tries  to exist as oppositely charged ions like

(1) $PCl _4^{+}$ and (2) $PCl _6^{-}$ as the ionic bonding enhances the crystalline nature .

also $PCl _4^{+}$  is tetrahedral , while $PCl _6^{-}$ is octahedral . these structure fit well into each other which gives more stability to solid structure .

Hence option D is correct.

Among the following, the number of compounds that can react with $PCl _{5}$ to give $POCl _{3}$ is: 


$O _{2},\ CO _{2},\ SO _{2},\ H _{2}O,\ H _{2}SO _{4},\ P _{4}O _{10}$

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

  1. 4

  2. 5

  3. 3

  4. 6

Show answer
Correct Option: A
Explanation:

$PCl$ on reaction with these $4$ compounds produces $POCl _3$:


$PCl _5+SO _2\rightarrow POCl _3+SOCl _2$
$PCl _5+H _2O\rightarrow POCl _3+2HCl$
$PCl _5+H _2SO _4\rightarrow SO _2Cl _2+2POCl _3+2HCl$
$6PCl _5+P _4O _{10}\rightarrow 10POCl _3$.

The most powerful chlorinating agent is :

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

  1. $\mathrm{P}\mathrm{Cl} _{3}$

  2. $\mathrm{Cl} _{2}\mathrm{O}$

  3. $\mathrm{P}\mathrm{Cl} _{5}$

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

Show answer
Correct Option: C
Explanation:

$PCl _{5}$ readily dissociates into $PCl _{3}$ and chlorine gas and therefore acts as a good chlorinating agent.

Which of the following pentahalides does not exist?

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

  1. $\mathrm{P}\mathrm{F} _{5}$

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

  3. $\mathrm{P}\mathrm{B}\mathrm{r} _{5}$

  4. $\mathrm{PI} _{5}$

Show answer
Correct Option: D
Explanation:

SI is too big for small P.
SI atoms cannot fil around small P. So $PI _{s}$ does not exist.