Chemistry

Chemical Bonding and Molecular Structure

1,420 Questions

This section tests your knowledge of chemical bonding, molecular structure, and hybridization. It covers ionic and covalent bonds, octet rule exceptions, and molecular geometry. These chemistry questions are common in various competitive entrance examinations.

Ionic and covalent bondsHybridisation of elementsOctet rule exceptionsMolecular geometryIntermolecular forces

Chemical Bonding and Molecular Structure Questions

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

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

  1. Ionic

  2. Polar covalent

  3. Non polar covalent

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

$Ca{H _2}$ is an example of :

  1. Ionic hydride

  2. Covelent hydride

  3. Metallic hydride

  4. Polymeric hydride
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Calcium hydride (CaH2) is formed by an alkaline earth metal and hydrogen, resulting in an ionic bond between the metal cation and the hydride anion.

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Which of the following pair behaves strong and weak base hydride :


$NH _3, PH _3, AsH _3, SbH _3, BiH _3$

  1. $NH _3, PH _3$
  2. $NH _3, BiH _3$
  3. $PH _3, BiH _3$
  4. $BiH _3, AsH _3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the group 15 hydrides, basicity decreases down the group as the lone pair becomes more diffuse and less available for donation. Thus, NH3 is the strongest base and BiH3 is the weakest.

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Which of the following hydrides is electron-precise hydride?

  1. $B _2H _6$
  2. $NH _3$
  3. $H _2O$
  4. $CH _4$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Methane $CH _4$ is electron-precise hydride.
Diborane $B _2H _6$ is electron-deficient hydride
Ammonia $NH _3$ and water $H _2O$ are electron-rich hydrides.

Elements of group 14 form electron-precise (having required number of electrons to write the Lewis structure ) form precise hydrides.
Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Which of the following exists as associated molecules due to hydrogen bonding?

  1. $NH _{3}$
  2. $H _{2}O$
  3. $HF$
  4. $HCl$
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

Due to good extent of hydrogen bonding (hydrogen bonding is more favoured if the hydrogen is attached to an electronegative atom) in A, B and C options, they exist in chains or in groups attached through hydrogen bonding.

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Ionic hydride among following is 

  1. $BeH _2$
  2. $NH _2$
  3. $CaH _2$
  4. $CuH _2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

CaH2 is a classic example of an ionic (saline) hydride formed by an alkaline earth metal. BeH2 is covalent due to high charge density, and NH2 is not a standard binary hydride (NH3 is).

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Among $CaH _2, NH _3, NaH$ and $B _2H _6$, which are covalent hydrides?

  1. $NH _3$ and $B _2H _6$
  2. $NaH$ and $CaH _2$
  3. $NaH$ and $ NH _3$
  4. $CaH _2$ and $B _2H _6$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$NH _3$ and $B _2H _6$ are the covalent hydrides and $CaH _2$ and $NaH$ are the ionic hydride.

$N$ and $B$ form covalent hydride as they have high electronegativity and small size.

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

The compound molecular in nature in gas phase but ionic in solid state is :

  1. $ PCl _5 $
  2. $ CCl _4 $
  3. $ PCl _3 $
  4. $ POCl _3 $

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

In gaseous and molten state $PCl _5$ is neutral molecule with trigonal bipyramidal symmetry.

In solid state $PCl _5$ is ionic which forms $PCl _4^{+}$, $PCl _6^{-}$. The cation and anion $PCl _4^{+}$, $PCl _6^{-}$ are tetrahedral and octahedral respectively.

Hence option A is correct.

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

According to  molecular orbital theory, the paramagnetism of $O _{2}$  molecule is due to presence of 

  1. Unpaired electrons in the bonding $\sigma $ molecular orbital
  2. Unpaired electrons in the anti- bonding $\sigma $ molecular orbital
  3. Unpaired electron in the bonding $\pi $ molecular orbital
  4. Unpaired electrons in the anti - bonding $\pi $ molecular obrital
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

Lake test of $Al^{3+}$ ion is based on adsorption of blue litmus on solid surface of :

  1. $Al$
  2. $Al(OH) _3$
  3. $Al _2O _3$
  4. $AlCl _3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Lake test of $Al^{3+}$ ion is based on adsorption of blue litmus on solid surface of $Al(OH) _3$. The dye aluminon is adsorbed by the gelatinous $Al(OH) _3$ precipitate to form lake coloured solution. This test is used as a confirmatory test for $Al^{3+}$ after precipitation of $Al(OH) _3$ with aqueous ammonia.

Multiple choice biology biotechnology and genetic engineering making use of enzymes genetic technology genetic engineering

Which of the following is a method of covalent bonding used during immobilisation?

  1. Diazotation

  2. Phosphorylation

  3. Dehydrogenation

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Covalent bonding is one of the commonly used methods of enzyme immobilization which engages the formation of covalent bonds between the enzymes & the support. Diazotation is a method of convalent bonding which displays the bonding between the amino group of support & tyrosyl or histidyl group of enzyme. 
So, the correct answer is 'Diazotation'