Exam 4: Acids and Bases

Complete the equation below for the protonation of cyclohexene with HCl. Show the movement of pairs of electrons with curved arrows and provide the structures of the conjugate acid and conjugate base.

Complete the equation below for the protonation of 2-butene with HBr. Show the movement of pairs of electrons with curved arrows and provide the structures of the conjugate acid and conjugate base.

What is the value of the equilibrium constant, K_eq, for the following reaction?

Which of the following compounds is the strongest acid?

The following correctly shows the electron flow for the given reaction.

The pK_a of acetic acid, CH₃COOH, is 4.76. What is the value of the equilibrium constant K_eq, for the following equilibrium? [The concentration of water in a dilute aqueous solution is 55 M] $\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{H}_{2} \mathrm{O}=\mathrm{H}_{3} \mathrm{O}^{\oplus}+\mathrm{CH}_{3} \mathrm{COO}^{\ominus}$

Which of the following is a feature of a Brønsted-Lowry base?

Which species is the conjugate acid in the following acid-base reaction?

Which of the following anions is the strongest base?

Which of the following has a pK_a value of approximately 25?

Which of the following is a definition of the activation energy of a reaction?

Which of the following compounds has the highest pK_a?

Provide the equation that relates the acid dissociation constant, K_a, to the pK_a of an acid.

What is the value of the equilibrium constant for the following equilibrium? $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}+\mathrm{HBr}\rightleftharpoons$$\mathrm{CH}_{3} \mathrm{CH}_{2} \stackrel{+}{\mathrm{O}} \mathrm{H}_{2}+\mathrm{Br}^{-}$ $\quad$$\mathrm{p} K_{\mathrm{a}}=-8$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\mathrm{p} K_{\mathrm{a}}=-1.74$

Provide a brief explanation, based on features of the molecules, for the following trend in pK_a values? CH₃CH₂OH > CF₃CH₂OH ethanol 2,2,2-trifluoromethanol 15.9 12.4

Which of the following is a feature of a Brønsted-Lowry acid?

Use curved arrows to show the movement of pairs of electrons in the following acid-base reaction and show the structures of the conjugate acid and conjugate base.

Consider the following reaction coordinate diagram. This reaction is endergonic.

What is the approximate pK_a value of HCl?

Consider the following reaction coordinate diagram. The free energy of activation is represented by the letter C.