Chemistry

Chemical Compounds and Reactions

505 Questions

Chemical compounds and reactions involve understanding the properties, colors, and formation of various chemical substances. Questions focus on identifying precipitates, observing color changes during reactions, and naming common compounds. This topic is a fundamental part of the chemistry syllabus for competitive exams.

identifying precipitateschemical reaction colorscompound namingcolloidal particle propertiesacid base reactions

Chemical Compounds and Reactions Questions

Multiple choice chemistry adsorption and colloids applications of colloids colloids around us the colloidal state

To stop bleeding from an injury ferric chloride can be applied
Which comment about the statement is justified?

  1. It is not true, ferric chloride is a poison
  2. It is true, ${Fe}^{3+}$ ions coagulate blood which is negatively charged sol
  3. It is not true, ${Cl}^{-}$ ions from positively charged sol, profuse bleeding takes place
  4. It is true, coagulation takes place because of formation of negatively charged sol with ${Cl}^{-}$ ions.

  5. It is not true, ferric chloride is ionic and gets into blood stream
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

To stop bleeding from an injury, Ferric chloride can be applied because of the following reason:

(A) $Fe^{3+}$ ions coagulate blood which is a negatively charged solution
(B) $Cl^−$ ions coagulate blood which is a positively charged solution

Blood being a colloidal solution, its coagulation by Hardy-Shuze's law states " Higher the charge on cation higher will be its efficiency to coagulate the colloidal solution" . Thus Option B is correct.

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

Choose the correct statement.

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
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

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

Is ${PCl} _{3}$ soluble in water?

  1. Not Soluble

  2. May be

  3. Partially soluble

  4. Soluble
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
like dissolve like. It means polar molecules dissolves in polar molecules and non-polar molecules.Molecules dissolves in non polar molecules $Water$ and $PCl _3$ both are polar molecules because of their shape and electronegative difference between $H$ and $O$ in water and $P$ and $Cl$ in $PCl _3$. Hence $PCl _3$ is solube in water.
$PCl _3$ dissolve in water to form phosphorous acid.
$PCl _3$ $+$ $3H _2O$  $\longrightarrow $   $H _3PO _3$ $+$ $3HCl$
Multiple choice chemistry acids and alkalis acids with carbonates reactions of acids and bases properties of acids and bases

Acid rain causes damage to the historical monuments like Taj Mahal. Why?

  1. Marble is made up of calcium carbonate

  2. Marble is made up of calcium hydroxide

  3. Marbles are made up of metal oxides

  4. None of above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Acid rain causes damage to the historical monuments and other buildings. For example Taj Mahal, which is made of marble, is getting damaged because of reaction with acid rain. Marble is calcium carbonate which reacts with the acid and thus gets corroded.

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

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

  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
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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 $sp^3$.