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 bonding and structure formal charge basics of chemical bonding types of bonds

A molecule with highest bond energy is:

  1. Fluorine

  2. Chlorine

  3. Bromine

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

Bond dissociation energy in $KJ mol^-1$
$F _2-158$
$Cl _2-244$ 
$Br _2-93$ 
$I _2-151$ 
Hence, in order of decreasing bond strength: 
$Cl _2>Br _2>F _2>I _2$
Fluorine is an anomaly. 

Bond strength decreases from chlorine to iodine as down the group, the atomic size becomes larger and thus the valence electron orbitals become more diffused, causing the overlap of orbitals to become less effective. Therefore the halogen-halogen bond becomes weaker from chlorine to iodine.Fluorine is an exception due to its extremely small size. The F-F bond length is so short that the lone pairs of electrons on the fluorine atoms repel each other and weakens the F-F bond. 

Multiple choice chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

In which of the following molecules partial charge separation does not take place?

  1. Chlorine

  2. Hydrochloric acid

  3. Water

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

Cl molecules are covalent in nature so it is non polar molecule. Non polar compound consists of molecules linked through chemical bonds arranged in such a way that the distribution of charges are symmetrical. Non polar bonds do not exhibit polarity and do not form ions in their solution. These compounds do not dissolve in water which is a polar molecule.

Multiple choice chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

The partial charge separation between the bonded atoms gives rise to ___________ in that compound.

  1. covalent character

  2. coordinate character

  3. ionic character

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

Partial charge separation between the bonded atoms gives rise to ionic character in the molecule due to the electronegativity difference, a quite small degree of polarization occurs.

Multiple choice chemistry classification of elements- the periodic table periodic trends in physical properties properties and trend trends in periodic table electronic configuration and valency electron configuration

If the E.N. value of Nitrogen in the pauling scale is 3.0, then he value in mulliken scale will be

  1. $11.2$
  2. $22.4$
  3. $8.4$
  4. $3.0$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Mulliken electronegativity (M) is related to the Pauling scale (P) by the approximate relation M = 2.8 * P^2 + 0.77 * P, or more commonly in introductory chemistry, M = 2.8 * P. Using the standard conversion factor of 2.8, 3.0 * 2.8 = 8.4.

Multiple choice chemistry classification of elements- the periodic table periodic trends in physical properties properties and trend trends in periodic table electronic configuration and valency electron configuration

The ionic radii of ${Rb}^{+}$ and ${I}^{-}$ are $1.46$ and $2.16$ $\mathring { A } $, respectively. The most probable type of structure exhibited by it is

  1. $CsCl$ type
  2. $NaCl$ type
  3. $ZnS$ type
  4. $Ca{F} _{2}$ type
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The radius ratio is calculated as r+/r- = 1.46 / 2.16 = 0.676. A radius ratio between 0.414 and 0.732 indicates an octahedral coordination geometry, which corresponds to the NaCl crystal structure.

Multiple choice chemistry classification of elements- the periodic table periodic trends in physical properties properties and trend trends in periodic table electronic configuration and valency electron configuration

Mulliken scale of elecrtonegativity uses the concept of:

  1. E. A. and EN of pauling

  2. E.A. and atomic size

  3. E.A. and I.P.

  4. E.A. and bond energy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Mulliken proposed that the arithmetic mean of the first ionization energy and the electron affinity should be a measure of the tendency of an atom to attract electrons.

Multiple choice chemistry classification of elements- the periodic table periodic trends in physical properties properties and trend trends in periodic table electronic configuration and valency electron configuration

If the ionisation potential is IP, electron affinity is EA and electronegativity is x then which of the following relation is correct.

  1. 2X-EA-IP=0

  2. 2EA-X-IP=0

  3. 2IP-X-EA=0

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Electron affinity: The amount of energy released when an electron is added to the outermost shell of one mole of an isolated gaseous atom in its lower energy state.

Ionisation energy: Minimum energy required to remove most loosly held outer most shell e – in ground state from an isolated gaseous atom is known as ionisation potential.

$\displaystyle X= \frac{IP+EA}{2}$

$2X-IP-EA=0$
Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

Metallic bond is formed by sharing of electrons between ______.

  1. Two atoms

  2. Many atoms

  3. Three atoms

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

Metallic bond is formed by sharing of electrons between many atoms A metallic bond is pretty different from covalent and ionic bonds, but the goal is the same: to achieve a lower energy state. Instead of a bond between just two atoms, a metallic bond is a sharing of electrons between many atoms of a metal element. Hence option B is correct.

Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

A metallic bond differs form a covalent bond in that:

  1. it is not directional

  2. it is not saturable

  3. the valence electrons are not attached to any particular atom

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Metallic bond is the force of attraction between many valence electrons and positive ions such that a single electron is attracted by many positive ions (also known as kernel). Hence it is non-directional and non-saturable.


Whereas covalent bond is formed by sharing of valence electrons between two particular atoms which makes it directional as well as saturable.

Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

The type of bond between atoms of calcium in a crystal of calcium is:

  1. Hydrogen bond

  2. Ionic bond

  3. Polar covalent bond

  4. Pure covalent bond

  5. Metallic bond
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The type of bond between atoms of calcium in a crystal of calcium is Metallic bond.
Metallic solids are the crystalline solids formed by atoms of the same metallic element. The bonding electrons are delocalised over entire crystal lattice and can move freely from one end to other. These bonding electrons forms sea of electrons whereas metal ions form a kernel. Metallic bond is the electrostatic attractive force between positively charged metallic ions and negatively charged delocalised electrons.

Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

Metallic bonding is explained by:

  1. electron sea model

  2. band model

  3. both A and B

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

In contrast to electrons that participate in both ionic and covalent bonds, electrons that participate in metallic bonds delocalize, forming a sea of electrons around the positive nuclei of metals. The availability of "free" electrons contributes to metals being excellent conductors.

Multiple choice ionic bond atomic structure and chemical bonding chemistry

A neutral atom of an element has a nucleus with nuclear charge $11$ times and mass $23$ times that of hydrogen. The element can form a stable charged ion by:

  1. losing 1 electron

  2. losing 2 electrons

  3. gaining 1 electron

  4. gaining 2 electrons
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Atomic number of hydrogen $= 1$.

$\therefore$ The atomic number of neutral atom $= 11$ & electronic configuration $= 2, 8, 1$. 
Therefore, on losing one electron, the atom forms the stable noble gas configuration as $2, 8$.

So, the correct option is A.