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 group 17 elements - general properties group 17 elements group 17 elements - properties

Compare oxygen and flourine in Ionic radius$\quad O^{2-} , F^-$:

  1. $\space O^{2-} = F^-$
  2. $\space O^{2-} < F^-$
  3. $\space O^{2-}> F^-$
  4. $\space O^{2-} \geq F^-$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Among the elements of same period the ion with more number of electrons and less number of protons is having more radius.If the number of electrons are same the ion with less number of protons is having more radius.

Here $\quad O^{2-} $and $ F^-$ both are having same 10 electrons but oxygen is having 8 protons(which can atrract outer electrons with less force than florine) and florine is having 9 protons.So the ionic radius of $\space O^{2-}>  F^-$

Hence option C is correct.

Multiple choice chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

Which is the most active element among folllowing?

  1. Chlorine

  2. Oxygen

  3. Sulfur

  4. Fluorine
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Most active element is Fluorine. The reduction potential of fluorine is very high. Hence, it is extremely reactive in nature. Also F-F bond energy is low (38 kcal/mol). The valence shell electron configuration of fluorine $2s^22p^5$  indicates that it has very strong tendency to take up one electron to attain stable noble gas configuration. Hence, it has high reactivity.

Multiple choice chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

A coordinate covalent bond is represented by an arrow from donor to acceptor.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Coordinate covalent bond is represented by an arrow from donor to acceptor.

Eg:NO $[NH _3 \to H]^+$
Coordinate covalent bond means donating a lone pair of electron of one atom to a vacant orbital of another atom.

Multiple choice chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

In the coordinate covalency,

  1. electrons are equally shared by the atoms

  2. electrons of one atom are shared between the two atoms

  3. hydrogen bond is formed

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The 2 electrons of an atom( generally lone pair) is donated by one atom to the other atom and it results in the formation of a coordinate bond.

Multiple choice chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

During the formation of hydronium ion, water molecule acts as donor.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A hydronium ion is written as ${ H } _{ 3 }{ O }^{ + }$. 

It is formed when something else donates a proton, or $H^+$ to a water molecule.
The $H^+$ will easily bond to one of the two lone pairs of electrons around the water molecule.

     ${ H }^{ + }+{ H } _{ 2 }O\longrightarrow { H } _{ 3 }{ O }^{ + }$

Multiple choice chemistry chemical bond and chemical equation coordinate bond types of bonds and properties chemical bonding and structure

Dative bond is present in the molecule :

  1. $NH _3$
  2. $CO _2$
  3. $NaCl$

  4. None of these.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A dative bond is a covalent bond between two atoms where one of the atoms provides both electrons that form the bond i.e. a kind of 2-center, 2-electron bond.

Here, covalent bond is present in $NH _3$ and $CO _2$, whereas ionic bond is present in $NaCl$.

So, there is no dative bond in  $NH _3$, $CO _2$ and $NaCl$.

Hence, option (D) is the correct answer.
Multiple choice chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

If pure $'p'$ orbitals are involved in molecule formation, then the shape of ${ H } _{ 3 }{ O }^{ + }$ will be:

  1. pyramidal

  2. tetrahedral

  3. angular

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

$ H _3O^+$ will have three bond pairs and one lone pair and shape same as $NH _3$ is therefore pyramidal. The hydroxonium ion is isoelectronic with ammonia and has an identical shape of pyramidal. 

So option $A$ is the correct option. 

Multiple choice chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

The dative bond is present in:

  1. $NH _{3}$
  2. $NH _{4}Cl$
  3. $PCl _{5}$
  4. $BF _{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When ammonium is formed, the fourth hydrogen is formed is attached by dative covalent bond because the only hydrogen nucleus is transferred from chlorine to nitrogen. The hydrogen electron left behind on the chlorine to form the negative chloride ion.