Tag: chemical bonding and structure

Questions Related to chemical bonding and structure

In which of the following molecules, is the covalent bond most polar?

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

  1. HI

  2. HBr

  3. HCl

  4. HF

Show answer
Correct Option: A
Explanation:

Polar covalent bond shows minimum electronegativity difference between the atoms.

$H=2.1,F=4,Cl=3,Br=2.8,I=2.5.$ 

So, $HI=0.4$ with the minimum difference is the most polar covalent bond.

Hence, option A is correct.

A molecule with highest bond energy is:

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

  1. Fluorine

  2. Chlorine

  3. Bromine

  4. Iodine

Show answer
Correct Option: B
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. 

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

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

  1. Chlorine

  2. Hydrochloric acid

  3. Water

  4. Ammonia

Show answer
Correct Option: A
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.

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

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

  1. covalent character

  2. coordinate character

  3. ionic character

  4. none of these

Show answer
Correct Option: C
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.

What is the formal charge on the chlorine atom in the oxyacid $HOClO _2$ if it contains single bonds ?

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

  1. $-2$

  2. $-1$

  3. $+1$

  4. $+2$

Show answer
Correct Option: D
Explanation:

formal charge= valence electrons-(lone electrons+bonds)
$=7-(2+3)=+2$

Metallic bond is formed by sharing of electrons between ______.

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

  1. Two atoms

  2. Many atoms

  3. Three atoms

  4. Four atoms

Show answer
Correct Option: B
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.

Iron is tougher than sodium because :

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

  1. iron atom is smaller

  2. iron atoms are more closely packed

  3. metallic bonds are stronger in iron

  4. none of these

Show answer
Correct Option: C
Explanation:
Iron is tougher than sodium because metallic bonds are stronger in iron.
Stronger is metallic bonding (FeFe has dd -subshell), more is hardness.

Hence, it is hard than Sodium like other alkali metals are soft.

So, the correct option is $C$

A solid which is transparent to visible light and whose electrical conductivity decreases with increase in temperature is formed by:

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

  1. Ionic bonding

  2. Metallic bonding

  3. Covalent bonding

  4. Van der Waals bonding

Show answer
Correct Option: C

A metallic bond differs form a covalent bond in that:

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

  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

Show answer
Correct Option: D
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.

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

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

  1. Hydrogen bond

  2. Ionic bond

  3. Polar covalent bond

  4. Pure covalent bond

  5. Metallic bond

Show answer
Correct Option: E
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.