Hybridization and Sigma and Pi Bonds: Quiz

7 questions

  1. Question 1EasyWhat is the hybridization of carbon in methane, CH₄?
    Show answer

    Answer: sp³

    Carbon has 4 bonded atoms and no lone pairs: 4 electron domains, so sp³, tetrahedral, 109.5°.

  2. Question 2EasyA double bond consists of:
    Show answer

    Answer: one σ and one π bond

    The first bond between two atoms is always σ (head-on); the second is a π bond (side-on overlap of p orbitals).

  3. Question 3MediumWhat is the hybridization of carbon in CO₂?
    Show answer

    Answer: sp

    Carbon is bonded to two O atoms with no lone pairs: 2 domains (each double bond counts once), so sp and linear.

  4. Question 4MediumWhat is the bond angle around an sp²-hybridized carbon with no lone pairs?
    Show answer

    Answer: 120°

    Three sp² hybrids lie in a plane, as far apart as possible: 120° (trigonal planar).

  5. Question 5MediumHow many σ and π bonds are in ethyne, HC≡CH?
    Show answer

    Answer: 3 σ, 2 π

    Two C–H bonds (2 σ) plus the C≡C (1 σ + 2 π): 3 σ and 2 π in total.

  6. Question 6MediumWhat is the hybridization of the oxygen atom in water?
    Show answer

    Answer: sp³

    O has 2 bonds and 2 lone pairs: 4 domains, so sp³. Lone pairs count as domains.

  7. Question 7HardWhy is the π bond in C=C weaker than the σ bond?
    Show answer

    Answer: Side-on overlap of p orbitals is smaller than head-on overlap

    Both bonds hold two electrons, but side-on overlap is less effective, so the π bond is weaker: C=C (614 kJ/mol) is less than twice C–C (348 kJ/mol).