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Questions Related to chemistry

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

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

$P 4 + 6Cl _2\, \rightarrow$_______

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

  1. $2P _2Cl _2$

  2. $4PCl _3$

  3. $PCl _6$

  4. $P _2Cl _5$

Show answer
Correct Option: B
Explanation:

The correct chemical equation is :

$P _4 + 6Cl _2 \rightarrow 4PCl _3$

$\mathrm{B}$ottle of $\mathrm{P}\mathrm{C}l _{3}$ is kept stoppered because it :

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

  1. explodes

  2. gets oxidized

  3. is volatalised

  4. reacts with moisture

Show answer
Correct Option: D
Explanation:

Solution:-
$PCl _3+3H _2O\rightarrow H _3\ PO _3+3HCl$


$PCl _3$ reacts rapidly and exothermically with water to form phosphorus acid ,$H _3PO _3$ and $HCl$.

Option D is correct.

The products of the hydrolysis of $\mathrm{P}\mathrm{Cl} _{3}$ are :

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

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

  2. $\mathrm{H}\mathrm{Cl},\ \mathrm{H} _{3}\mathrm{P}\mathrm{O} _{3}$

  3. $\mathrm{Cl} _{2},\ \mathrm{H} _{3}\mathrm{P}\mathrm{O} _{3}$

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

Show answer
Correct Option: B
Explanation:

 Hydrolysis of $PCl _3$ gives:

$2PCl _3+6H _2O\rightarrow 2H _3PO _3+6H+$

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

Option B is correct.

The products formed by the complete hydrolysis of $P{Cl} _{3}$ are:

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

  1. ${H} _{3}{PO} _{3}$ and $HCl$

  2. $PO{Cl} _{3}$ and $HCl$

  3. ${H} _{3}{PO} _{4}$ and $HCl$

  4. ${H} _{4}{P} _{2}{O} _{7}$ and $HCl$

Show answer
Correct Option: A
Explanation:
The products formed by the complete hydrolysis of $PCl _3$ are as follow:
$PC{ l } _{ 3 }+3{ H } _{ 2 }O\rightarrow { H } _{ 3 }P{ O } _{ 3 }+3HCl$

${ H } _{ 3 }P{ O } _{ 3 }$ and $HCl$ are the products formed.

On hydrolysis, $PCI _3$ 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. $POCI _3$

  4. $HPO _3$

Show answer
Correct Option: A
Explanation:
$PCl _{3}$ on hydrolysis gives $HCl$ and $ H _{3}PO _{3}$

$PCl _{3}+ 3H _{2}O\rightarrow H _{3}PO _{3}+3HCl$

Phosphorus trichloride reacts violently with water forming phosphorous acid.

Option (A) is correct .

Choose the correct statement.

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

  1. White or yellow phosphorus is stored under water

  2. Ignition temperature of red phosphorus is low

  3. Black phosphorus is non crystalline in nature

  4. Phosphorus does not form hydrides

Show answer
Correct Option: A
Explanation:

Due to low ignition temperature of white phosphorus, it undergoes oxidation in presence of air which slowly raises its temperature and after a few moments it catches fire spontaneously. Due to this reason, it is stored under water. Ignition temperature ofred phosphorus is high Black phosphorus is crystalline in nature. Phosphorus forms a number of hydrides