Polarity of Bonds and Properties of Nitrogen Molecule (N₂)

Q5. Which of the following bonds is the most polar?

Background

Topic: Bond Polarity and Electronegativity

This question tests your understanding of how differences in electronegativity between two atoms affect the polarity of a chemical bond. The greater the difference, the more polar the bond.

Key Terms and Formulas

• Electronegativity: A measure of an atom's ability to attract shared electrons in a bond.

• Bond Polarity: Determined by the difference in electronegativity ($\Delta EN$) between the two atoms.

• Polarity Formula: $\Delta EN = |EN_1 - EN_2|$

Step-by-Step Guidance

1. List the electronegativity values for each atom in the bonds (refer to your equation sheet or periodic table).

2. Calculate the difference in electronegativity ($\Delta EN$) for each bond option: C–H, S–Cl, H–Cl, Al–B, S–F.

3. Compare the $\Delta EN$ values. The bond with the largest difference is the most polar.

4. Recall that a higher $\Delta EN$ means a greater separation of charge and thus higher polarity.

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Q6. Which of the following statements is/are true about the nitrogen diatomic molecule (N₂)?

Background

Topic: Molecular Structure, Bond Order, and Octet Rule

This question tests your knowledge of the properties of N₂, including bond type, bond order, and electron configuration.

Key Terms and Formulas

• Bond Order: The number of chemical bonds between a pair of atoms. For N₂, bond order is calculated using molecular orbital theory.

• Octet Rule: Atoms tend to have eight electrons in their valence shell for stability.

• Polar Covalent Bond: A bond where electrons are shared unequally due to differences in electronegativity.

• Bond Order Formula: $\text{Bond Order} = \frac{1}{2} (\text{Number of bonding electrons} - \text{Number of antibonding electrons})$

Step-by-Step Guidance

1. Recall the structure of N₂: two nitrogen atoms triple-bonded together.

2. Determine if the N–N bond is polar or nonpolar by comparing the electronegativities of the two nitrogen atoms.

3. Calculate the bond order for N₂ using the molecular orbital diagram or by counting the bonds (single, double, triple).

4. Check if each nitrogen atom achieves a full octet in the N₂ molecule.

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