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The carbon atom

Key Concepts and Summary

We can use hybrid orbitals, which are mathematical combinations of some or all of the valence atomic orbitals, to describe the electron density around covalently bonded atoms. These hybrid orbitals either form sigma (σ) bonds directed toward other atoms of the molecule or contain lone pairs of electrons. We can determine the type of hybridization around a central atom from the geometry of the regions of electron density about it. Two such regions imply sphybridization; three, sp2 hybridization; four, sp3 hybridization; five, sp3d hybridization; and six, sp3d2 hybridization. Pi (π) bonds are formed from unhybridized atomic orbitals (p or dorbitals).

Chemistry End of Chapter Exercises

  1. Why is the concept of hybridization required in valence bond theory?
  2. Give the shape that describes each hybrid orbital set:(a) sp2(b) sp3d(c) sp(d) sp3d2
  3. Explain why a carbon atom cannot form five bonds using sp3d hybrid orbitals.
  4. What is the hybridization of the central atom in each of the following?(a) BeH2(b) SF6(c) PO43−(d) PCl5
  5. A molecule with the formula AB3 could have one of four different shapes. Give the shape and the hybridization of the central A atom for each.
  6. Methionine, CH3SCH2CH2CH(NH2)CO2H, is an amino acid found in proteins. Draw a Lewis structure of this compound. What is the hybridization type of each carbon, oxygen, the nitrogen, and the sulfur?
  7. Sulfuric acid is manufactured by a series of reactions represented by the following equations:

    Draw a Lewis structure, predict the molecular geometry by VSEPR, and determine the hybridization of sulfur for the following:(a) circular S8 molecule(b) SO2 molecule(c) SO3 molecule(d) H2SO4 molecule (the hydrogen atoms are bonded to oxygen atoms)