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 nature of things objects that float or sink substances that sink or float soluble and insoluble substances

In the solvation of $NaCl$ in water, which of the following occur ?

  1. Hydrogen atom interacts with $Cl^-$ atom
  2. Oxygen atom interacts with $Na^+$ atom
  3. Both $A$ and $B$

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

In the water molecule oxygen has higher electronegativity than hydrogen thus has a partial negative charge and hydrogen has a partial positive charge. So during the solvation of NaCl in water, hydrogen atoms interact with chlorine anion and oxygen interact with sodium cation.

Multiple choice

What type of ions do bases release into a solution?

  1. Nitrogen ions

  2. Hydrogen ions

  3. Hydroxide ions

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

According to the Arrhenius definition, bases are substances that dissociate in aqueous solution to release hydroxide ions (OH-).

Multiple choice chemistry lattice energy born-haber cycle born-haber cycles energy cycles

Select correct statement.

  1. Both lattice energy and hydration energies decrease with ionic size.

  2. Lattice energy can be calculated using Born-Haber cycle.

  3. If the anion is larger compared to the cation, the lattice energy will remain almost constant within a particular group.

  4. All the above are correct statements.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

All the given statements are correct.
(A) Both lattice energy and hydration energies decrease with ionic size With large size, the charge is more dispersed. hence, the extent of hydration is smaller. Also the packing is inefficient.
(B) Lattice energy can be calculated using Born-Haber cycle The BornHaber cycle is an approach to analyze reaction energies. The cycle is concerned with the formation of an ionic compound from the reaction of a metal  (often a Group I or Group II element) with a halogen.
(C) If the anion is larger compared to the cation, the lattice energy will remain almost constant within a particular group

Multiple choice chemistry lattice energy born-haber cycle born-haber cycles energy cycles

Which of the following bonds has the highest bond energy?

  1. Si-Si

  2. Si=Si

  3. Si-O

  4. Si=O
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Bond energy generally increases with bond order. Si=O is a double bond and involves a highly electronegative atom, leading to a very strong bond compared to single bonds or Si-Si bonds.

Multiple choice chemistry lattice energy born-haber cycle born-haber cycles energy cycles

For the maximum ionic character during bond formation ,_________ on cation and a __________ anion are required.

  1. low charge, high charge

  2. low charge, low charge

  3. high charge , no charge

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
For an ionic interaction, both the cation and the anion should possess low charges. If the degree of polarization is quite small, ionic bonds are formed,
Otherwise, with higher degree of polarization, covalent bonds are formed
Ionic bonds result from a redox reaction in which the atoms of an element , which (usually metal) has low ionization energy, give away some of their electrons to achieve a stable electronic configuration
Multiple choice chemistry chemical bond and chemical equation properties of covalent compounds types of bonds and properties covalent bond

Which statement about bonding is not correct?

  1. Carbon can form four single covalent bonds

  2. Chlorine atoms react to gain a noble gas electronic structure

  3. Covalent bonding involves losing and gaining electrons
  4. Hydrogen molecules have the formula $H _{2}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation


Solution:- (C) Covalent bonding involves losing and gaining electrons

Covalent bonding involves sharing of electrons while the losing and gaining of electrons is found in ionic bonding.

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.