1. A Review of General Chemistry

What orbitals contain the electrons represented as lone pairs in the structures of quinoline, indole, imidazole?

What orbital do the lone-pair electrons occupy in each of the following compounds?

a.

b.

c.

In addition to radicals, anions, and cations, a fourth class of reactive intermediates is carbenes. A neutral species, the simplest carbene has a molecular formula of CH₂.

(b) What are the hybridization and shape of the central carbon of CH₂?

Predict the hybridization of the indicated atoms.

(b)

For the following partial structures, the σ bond is shown. Add the indicated number of π bonds, being sure to specify the orientation (that is, x, y, or z axis) of the p orbitals used.

(e)

What orbitals are used to form the carbon–carbon s bond between the highlighted carbons?

a.

b.

c.

Predict the hybridization and geometry of the carbon and nitrogen atoms in the following molecules and ions. (Hint: Resonance.)

d.

Predict the hybridization and geometry of the carbon and nitrogen atoms in the following molecules and ions. (Hint: Resonance.)

f.

Predict the hybridization and geometry of the carbon and nitrogen atoms in the following molecules and ions. (Hint: Resonance.)

e.

What orbitals contain the electrons represented as lone pairs in the structures of purine, and pyrimidine?

Use hybrid orbitals to draw the following molecules.

(a)

Use hybrid orbitals to draw the following molecules.

(b)

Use hybrid orbitals to draw the following molecules.

(c)

Use hybrid orbitals to draw the following molecules.

(d)

Draw the molecular orbital picture of the following molecules and ions. In each, how many electrons are in the p orbital on the central atom? (b) BH₃