Class 9

9.3.4 Non-Polar and Polar Covalent Bond

This is the fourth lecture from Chapter 3: “Chemical Bonding” in the new Class 9 Chemistry book (Punjab Board – PCTB). It discusses the two types of covalent bonds: non-polar covalent bond and polar covalent bond. The lecture also includes a multiple-choice quiz, short question and long question notes.

MCQs Based Quiz

9.3.4 Non-Polar and Polar Covalent Bond

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A covalent bond in which bond pair is shared equally between both atoms is called:

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A covalent bond in which the bond pair is not shared equally between both atoms is called:

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Which type of covalent bond has partially positive and negative atoms?

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A non-polar covalent bond is formed between atoms with:

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A polar covalent bond is formed between atoms with:

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In a polar covalent bond, which atom gets a partial positive charge?

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In a polar covalent bond, which atom gets a partial negative charge?

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If A and B are two different atoms with unequal electronegativities and share a bond pair, what type of bond is formed between them?

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If two similar atoms share a bond pair, what type of bond is formed between them?

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A ___ is a bond in which the bond pair electrons lie exactly at the center of the two bonded atoms.

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A ___ is a bond in which the bond pair electrons lie closer to one atom than the other.

Your score is

The average score is 100%

Short Questions

Q1. What is a non-polar covalent bond?

A covalent bond formed between two identical atoms, where the bond pair electrons lie in the middle of the two atoms, is called a non-polar covalent bond.

Example: The covalent bond in $\ce{{H}-{H}}$ is a non-polar covalent bond.

Q2. How would you define a polar covalent bond?

A polar covalent bond is formed between two non-identical atoms, where the bond pair of electrons lies closer to the more electronegative atom.

Example: The covalent bond in $\ce{\overset{\delta+}{H}-\overset{\delta-}{Cl}}$ is a polar covalent bond.

Q3. What type of covalent bonds are present in a water molecule.

The bonds in water molecules are polar. The oxygen atom has a partial negative charge, while the hydrogen atoms have partial positive charges. This is because oxygen atoms are more electronegative than hydrogen atoms.

Water Molecule Structure With Partial Charges

Descriptive Question

Q1. Write a note on non-polar and polar covalent bonds.

Non-Polar Covalent Bond:

Covalent bond formed between atoms with similar electronegativities is called a non-polar covalent bond.

Formation of a Non-Polar Covalent Bond in Hydrogen Molecule:

  1. Two hydrogen atoms come closer together and share a bond pair.
  2. Because both of these atoms are identical, there is no electronegativity difference between them.
  3. Due to this, bond pair is shared equally between them and the electrons lie exactly in the center of the two atoms.

Hydrogen Molecule Structure

Polar Covalent Bond:

Covalent bond formed between atoms with different electronegativities is called a non-polar covalent bond.

Formation of a Polar Covalent Bond Between $HCl$ Molecule:

  1. Hydrogen and chlorine atoms come closer and share a bond pair.
  2. Because both of these atoms are non-identical and there is an electronegativity difference between them.
  3. Due to this, the bond pair is not shared equally, and the electrons lie closer to the more electronegative chlorine atom.
  4. Hydrogen atom gets a partial positive charge (δ+), and chlorine atom gets a partial negative charge (δ–).

Hydrogen Chloride Structure (HCl)

Q2. What is the difference between a non-polar covalent bond and a polar covalent bond?

Non-Polar Covalent Bond

Polar Covalent Bond

Covalent bond formed between atoms with similar electronegativities is called a non-polar covalent bond.

Covalent bond formed between atoms with different electronegativities is called a non-polar covalent bond.

Shared pair of electrons lies in the middle of the two bonded atoms.

Shared pair of electrons lies closer to the more electronegative atom.

Usually formed between identical atoms.

Usually formed between non-identical atoms.

None of the atoms is partially charged.

More electronegative atom has a partial negative charge (δ+), while the other atom has a partial positive charge (δ–).

Examples: H2, Cl2, N2, O2

Examples: H2O, HCl