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

Choose the correct options:

  1. PCl$ _5$ (solid) dissociates into PCl$ _4^+$ and PCl$ _6^-$.
  2. LiH reacts with AlH$ _3$ forming LiAlH$ _4$.
  3. $NH _3$ is protonated.
  4. $H _3PO _2$ on heated forms $PH _3$ and $H _3PO _3$.
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

PCl$ _5$ (solid) dissociates into PCl$ _4^+$ and PCl$ _6^-$. LiH reacts with AlH$ _3$ forming LiAlH$ _4$. These are facts. $NH _3$ is not protonated. On protonation, it forms $NH _4^+$ion. $H _3PO _2$ on heating does not form $PH _3$ and $H _3PO _3$.

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

In the given reaction $CI$  replaces one of the H-atoms in $CH _3CH _2OH$. This $H$ is of :


$PCI _5+C\underset{\overline{X}}{H _3}C\underset{\overline{Y}}{H _2}\underset{\overline{Z}}{OH} \longrightarrow$

  1. C (in X)

  2. C (in Y)

  3. O (in Z)

  4. any of X, Y and Z
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the reaction of ethanol (CH3CH2OH) with PCl5, the hydroxyl group (-OH) is replaced by a chlorine atom. This involves the breaking of the O-H bond (Z position) and the C-O bond.

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

The solid $PCl _5$ exists as :

  1. $PCl _3$
  2. $PCl _4^+$
  3. $PCl _6^-$
  4. $PCl _4^+$ and $PCl _6^-$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In solid state, $PCl _5$  prefers to exist as oppositely charged ions like $[PCl _4]^+$ & $[PCl _6]^-$ as the ionic bonding enhances the crystalline nature.

Also, $[PCl _4]^+$ is tetrahedral while $[PCl _6]^-$ is octahedral, these structures fit well into each other providing extra stability to the soild structure.

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

Solid crystalline $PCI _5$ has structure which of the following?

  1. Bi-pyramidal

  2. Octahedral and tetrahedral ions

  3. Square-pyramidal

  4. Pentagonal

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In solid state, $PCl _5$ prefers to exist as oppositely charged ions like $[PCl _4]^+$ & $[PCl _6]^-$ as the ionic bonding enhances the crystalline nature. Also, $[PCl _4]^+$ is tetrahedral while $[PCl _6]^-$ is octahedral, these structures fit well into each other providing extra stability to the soild structure.

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

In crystalline state $PCl _5$ exists as :

  1. $[PCl _4]^+Cl^-$
  2. $[PCl _4]^+[PCl _6]^-$
  3. $[PCl _3]^{2+}+2Cl^-$
  4. $[PCl _6]^+[PCl _4]^-$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In solid state, $PCl _5$ prefers to exist as oppositely charged ions like $[PCl _4]^+ [PCl _6]^-$ as ionic bonding enhances the crystalline nature. Also, $[PCl _4]^+$ is tetrahedral while $[PCl _6^-]$ is octahedral. These structures fit well into each other providing extra stability to the solid structure.


Hence, the correct option is (B).

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

What is the hybridization state of cation part of solid $PCl _5$?

  1. $sp^3d^2$
  2. $sp^2$
  3. $sp^3$
  4. $sp^3d$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In solid state, $PCl _5$ prefers to exist as oppositely charged ions like $[PCl _4]^+ PCl _6^-$ as ionic bonding enhances the crystalline nature. Also, $[PCl _4]^+  = sp^3$ is tetrahedral while $[PCl _6^-]$ is octahedral. These structures fit well into each other providing extra stability to the soild structure.

Thus, solid $PCl _5$ exist as $[PCl _4]^+[PCl _6]^-$
The cationic part of $PCl _5$ is$[PCl _4]^+$.
In $PCl _4^+$, Phosphorous forms $4\ \sigma-bonds$. 
Hence, the hybridization is $sp^3$.

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

In presence of small amount of water, $PCl _5$ hydrolyzes to form :

  1. $PCl _3$

  2. POCl
  3. $POCl _3$
  4. $H _3PO _3$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In limited amount of water,
$PCl _5 (s)+H _2O (l)\rightarrow POCl _3(l) + 2HCl(aq)$
In large amount of water,
$PCl _5(s) +4H _2O(l)\rightarrow H _3PO _4+ 5HCl$

Hence, the correct option is (C).

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

Which of the following statements is/are correct?

  1. Solid $PCl _5$ exists as tetrahedral $PCl^{+} _{4}$ and octahedral $PCl^{-} _{6}$ ions.
  2. Solid $PBr _5$ exists as $PBr^{+} _{4}Br^{-}$.
  3. Solid $N _2O _5$ exists as $NO^{-} _3$ and $NO^{+} _{2}$.
  4. Oxides of phosphorus $P _2O _3$ and $P _2O _5$ exist as monomers.
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

Solid $PCl _5$ exists as tetrahedral $PCl^{+} _{4}$ and octahedral  $PCl^{-} _{6}$ ions.
$2PCl _5 \rightleftharpoons [PCl _4]^+ (tetrahedral) + [PCl _6]^-(octahedral)$
Solid $PBr _5$ exists as $PBr^{+} _{4}Br^{-}$.
$PBr _5 \rightleftharpoons [PBr _4]^+(tetrahedral) Br^-$
Solid $N _2O _5$ exists as $NO^{-} _3$ and $NO^{+} _{2}$.
$N _2O _5 \rightleftharpoons NO^{-} _3 + NO^{+} _{2}$
Oxides of phosphorus $P _2O _3$ and $P _2O _5$ exist as dimers $P _4O _6$ and $P _4O _{10}$. 

All these are facts. Thus, the options A, B and C are correct and option D is incorrect.

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

In the following reactions :
$(i) P{Cl} _{5}+{SO} _{2}\rightarrow A+B$
$(ii) A+MeCOOH\rightarrow C+{SO} _{2}+HCl$
$(iii) 2C+{Me} _{2}Cd\rightarrow 2D+CD{Cl} _{2}$ The compound (C) is:

  1. $Me-CH -Cl _2$
  2. $Me-CH _2 -Cl$
  3. $Me-\underset { \parallel \\ O }{ C } -Cl$
  4. $Me-C -Cl _3$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$(i) P{Cl} _{5}+{SO} _{2}\rightarrow SO{Cl} _{2} (A)+PO{cl} _{3} (B)$

(ii) $SO{Cl} _{2}+MeCOOH\rightarrow Me-\underset { \parallel \ O }{ C } -Cl (C)+{SO} _{2}+HCl\$