Chemistry

Chemical Bonding and Molecular Structure

1,277 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 introduction to mole gas laws and mole concept atoms and molecules chemistry mole concept chemical formula and mole concept

Which of the following molecules specie has the minimum number of lone pairs ? 

  1. $ X _eF _4 $
  2. $ BF^- _4 $
  3. $ ICI _3 $
  4. $ BeF _2 $
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

BeF2 has a linear structure with no lone pairs on the central Beryllium atom. XeF4 has 2, BF4- has 0 (but is an ion), and ICl3 has 2. However, BeF2 is the neutral molecule with zero lone pairs on the central atom.

Multiple choice chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

A neutral atom of an element with nuclear charge 11 times and mass 23 times that of hydrogen. Find the ratio of electrons to protons present in its stable ion.

  1. 1:1

  2. 5:6

  3. 10:11

  4. 12:11
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Protons in neutral atom = nuclear charge = 11

Electrons in neutral atom = 11
Mass = 23 

Element = Sodium
Ion = $Na^+$
Electrons in ion = 11-1 = 10
Protons in ion = 11
Ratio of electron to proton = 10:11

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

What is the hybridization of Phosphorus Trichloride?

  1. ${sp}^{3}$
  2. ${sp}^{2}$
  3. ${sp}$

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

The hybridization of ${PCl} _{3}$ is ${sp}^{3}$. Phosphorus has five electrons in its outermost shell. Thus it forms three sigma bonds with three neighbouring Chlorine atoms. The remaining two electrons remain as a lone pair on Phosphorus atom. Thus these three sigma bonds and one lone pair, make this molecule ${sp}^{3}$ hybridized.

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.