Exam 2: Polar Covalent Bonds; Acids and Bases

Guanidine is a fairly strong amine base that is attached to the amino acid arginine. Draw three resonance forms for the conjugate acid of guanidine. guanidine

Which of the following molecules has a dipole moment?

Refer to the following equation to answer the question(s) below. -Refer to instructions. Will this reaction take place as written in the forward direction? Explain.

Label the acid and base in each reaction below. -Label:

Complete this acid-base reaction, and label the acid, base, conjugate base, and conjugate acid.

Use the convention δ−/δ+ and the crossed arrow ( ) to show the direction of the expected polarity of the indicated bonds in the following compound(s). -Refer to instructions. The C−F bond in fluorobenzene,

Draw the conjugate base of each species.

Use the curved arrow method to show the electron movement, and label the acid, base, conjugate acid, and conjugate base.

Refer to the following equation to answer the question(s) below. -Refer to instructions. The strongest Brønsted-Lowry acid in the equation is indicated by letter _____.

Refer to the following equation to answer the question(s) below. -Refer to instructions. The strongest Brønsted-Lowry base in the equation is indicated by letter _____.

Explain why phenol has a lower pK_a than ethanol. phenol ethanol

Identify the reactants and product in the reaction below as acids or bases and specify whether they are Lewis and/or Brønsted-Lowry.

Rank the following in order of decreasing importance as a contributing resonance structure to the molecular structure of acetone, CH₃COCH₃ (more important > less important). A B C

Indole is pleasant smelling in highly dilute solutions and has been used in perfumery. Use the structure of indole, below, to answer the following question(s). -Refer to instructions. Indole can function as a Lewis base in the presence of strong acid. Formulate a reaction, using a generic acid (HA), showing electron flow with arrows, that demonstrates this reactivity of indole.

Draw a Lewis structure for each of the following. a)hydroxylammonium ion: ⁺NH₃OH. b)azide ion: (N₃−)

The condensed structure for dimethyl ether looks symmetrical. However, dimethyl ether has a dipole moment. Draw a structure that explains this and indicate the expected direction of the molecular dipole moment. dimethyl ether

Which of the following molecules would exhibit the largest dipole moment?

In aromatic nitration reactions, nitric acid (HNO₃) is used in conjunction with the stronger acid, sulfuric acid, H₂SO₄, to form an intermediate. Which of the following could be the formula for this intermediate?

The visual pigment in animal cells consists of an isomer of retinal linked to the protein opsin, as shown below. Write an alternative resonance form for this species that shows the positive charge situated on the starred carbon instead of the nitrogen atom and include the curved arrows to show the electron flow.

Draw two resonance forms for the cyclopentadienyl radical.