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 chemistry chemical bond and chemical equation properties of covalent compounds types of bonds and properties covalent bond

Compound $X$ consists of molecules.
In the liquid state X will

  1. becomes ionic

  2. be an electrolyte but not conduct electricity.

  3. conduct electricity only

  4. not conduct electricity

  5. non of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Compound X consists of molecules, so its covalent compounds and dont have any charged ions to conduct electricity so it will not conduct electricity.

Multiple choice chemistry chemical bond and chemical equation properties of covalent compounds types of bonds and properties covalent bond

Butane is:

  1. ionic compound

  2. noble gas

  3. polar covalent compound

  4. non-polar covalent compound
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Butane can be written as $CH _3-CH _2-CH _2-CH _3$. The electronegativities of Carbon and hydrogen are almost same and hence none of them is more electronegative than the other. Thus the compound is non polar in nature, as the electrons are equally distributed on the molecule.

Butane is an organic molecule and the bonds are formed by mutual sharing of electrons between the atoms. Hence, butane is a covalent compound.
Option D is the correct answer.

Multiple choice chemistry chemical bond and chemical equation properties of covalent compounds types of bonds and properties covalent bond

More covalent character is found in 

  1. $SnCl _4$
  2. $KCl$
  3. $CaCl _2$
  4. $SnCl _2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

According to Fajan's rule, covalent character increases with the charge on the cation. SnCl4 has a +4 charge on the tin ion, which is higher than the +2 charge in SnCl2 or the +1 charge in KCl/CaCl2, leading to greater polarization and more covalent character.

Multiple choice chemistry chemical bond and chemical equation properties of covalent compounds types of bonds and properties covalent bond

Covalent bond is present in which of the following molecule?

  1. Sodium Chloride

  2. carbon dioxide

  3. Sodium Bromide

  4. All of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Carbon dioxide $CO _2$ is covalent compound. In this molecule, two non-metals carbon and oxygen share their electrons to form covalent bonding. Remaining all molecules shows formation of ionic bonding.

Multiple choice chemistry chemical bond and chemical equation properties of covalent compounds types of bonds and properties covalent bond

Maximum number of bonds between two atoms of a covalent bond can be:

  1. four

  2. three

  3. two

  4. one
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Covalent bonds between atoms are quite strong, but attractions between molecule/compounds  or intermolecular forces, can be relatively weak. Covalent compounds generally have low boiling and melting points, and are found in all three physical states covalent bonds between atoms are quite strong, but attractions between molecules/compounds or intermolecular forces, can be relatively work. Covalent compounds generally have low boiling and melting points, and are found in all three physical states at room temperature. at room temperature.

Multiple choice chemistry chemical bond and chemical equation properties of covalent compounds types of bonds and properties covalent bond

Two compounds of A and B have similar formula $AX _3$ and $BX _3$ respectively. But, the compound of A has the dipole moment and dipole moment of the compound of B is zero. Which of the following statements is true regarding compounds of A & B?

  1. A and B are iso structural.

  2. A may have lone pair on central atom whereas B has no lone pair.

  3. A and B differ wrt type of hybridisation of central atom.

  4. All the above.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A and B differ wrt type of hybridization of central atom. 'B' may have lone pair on central atom whereas 'A' has no lone pair.
'A' has dipole moment as it is trigonal planar in which individual bond dipoles cancel each other and dipole moment of 'B' is zero as it has pyramidal geometry in which individual bond dipoles do not cancel each other. 

Multiple choice chemistry chemical bond and chemical equation properties of covalent compounds types of bonds and properties covalent bond

Assertion : $CH _3Cl$ is a polar molecule.
Reason : The Lewis diagram of polar molecules always has at least one lone pair of electrons.

  1. Assertion and Reason are correct and Reason is the correct explanation of Assertion

  2. Both the Assertion and Reason are correct and Reason is not the correct explanation of Assertion

  3. Assertion is correct but Reason is not correct

  4. Assertion is not correct but Reason is correct

  5. Both the Assertion and Reason are not correct
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Compound in statement 1 must be $C{ H } _{ 3 }Cl$.Since carbon,hydrogen and chlorine have different electronegativity,the bonds are polar in nature. Moreover, there is symmetry in the structure of the molecule, so there is a net dipole moment hence it is a polar molecule.

It is not a necessary condition that there has to at least one lone pair of electrons for a molecule to be polar. $C{ H } _{ 3 }Cl$ is an example.

Multiple choice chemistry chemical bond and chemical equation properties of covalent compounds types of bonds and properties covalent bond

Which of the following statements is/are true?

  1. Covalent bonds are directional.

  2. Ionic bonds are non-directional.

  3. A polar bond is formed between two atoms which have the same electronegativity value.

  4. The presence of polar bonds in a polyatomic molecule suggests that it has zero dipole moment.
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

Covalent bonds are directional and ionic bonds are nondirectional. A polar bond is formed between two atoms which have different electronegativity value. The presence of polar bonds in a polyatomic molecule suggests that mostly it has non-zero dipole moment.

Multiple choice chemistry chemical bond and chemical equation properties of covalent compounds types of bonds and properties covalent bond

$A,\ B,\ C$ are three substances. $A$ does not conduct electricity in the solid, molten state and aqueous solution. $B$ conducts electricity both in the fused and aqueous states, while $C$ conducts electricity only in the aqueous state. In solid state neither $B$ nor $C$ conducts electricity. Which of the following statements is/are true regarding $A,\ B$ and $C $?

  1. $A$ has polar covalent linkage
  2. $A$ has non-polar covalent linkage
  3. $B$ is ionic in nature

  4. Cation has polar covalent bonds
Reveal answer Fill a bubble to check yourself
B,C,D Correct answer
Explanation
$A$ does not conduct electricity in the solid and molten state suggests that $A$ is not an ionic compound and it can be a covalent compound.
$A$ is not conducting electricity in aqueous solution also, it suggests that all the element in compound $A$ has the same electronegativity.
Hence, $A$ can be non-polar covalent compound that means it has non-polar covalent linkage.
$B$ conducts electricity in a fused state and in aqueous states, This represents that the electronegativity difference in the compound is very high.
Hence, $B$ can be an ionic bond
$C$ conducts electricity in only in the aqueous state. It means that $C$ does not conduct electricity in a molten state that means $C$ is not an ionic compound.
It can be a covalent compound and as it is conducting electricity in the aqueous state, there must be small electronegativity difference.
Hence, $C$ can be a polar covalent compound.
Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

The bonds generally formin compounds of Actinoids are:

  1. convalent

  2. ionic

  3. coordinate covalent

  4. metallic
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Actinoids are highly electropositive elements, and their compounds are predominantly ionic in nature due to the large size of the ions and the relatively low electronegativity of the metals.

Multiple choice chemistry lattice energy defining lattice energy ionic or electrovalent bond energy cycles

The stability of an ionic compound is mostly due to:

  1. ionization energy

  2. electron affinity

  3. lattice energy

  4. electronegativity
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Lattice energy is a measure of energy released in ionic crystals when the ions are brought together from infinity. It measures the attraction between ions so that they are held in a position. Ionic compound stability is mostly due to lattice energy.

Multiple choice chemistry lattice energy defining lattice energy ionic or electrovalent bond energy cycles

Lattice energy of ionic compounds depend upon:

  1. packing of ions only

  2. charge and size of ions

  3. charge on ion only

  4. size of ions only
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Lattice energy is defined as the heat of formation for ions of opposite charge in the gas phase to combine into an ionic solid. It is directly proportional to the charge on the ions and inversely proportional to the size of the ions.