91Ó°ÊÓ

Which hydrogen in each molecule is most acidic? a. \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) b. \(\mathrm{HOCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{NH}_{2}\) c. \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{NCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{NH}_{2}\)

The \(\mathrm{p} K_{\mathrm{a}}\) of nitromethane \(\left(\mathrm{CH}_{3} \mathrm{NO}_{2}\right)\) is 10 , making its \(\mathrm{C}-\mathrm{H}\) bond more acidic than most \(\mathrm{C}-\mathrm{H}\) bonds. Explain.

The indicated hydrogen in 1,4 -pentadiene is more acidic than the indicated hydrogen in pentane. Explain.

Dimethyl ether \(\left(\mathrm{CH}_{3} \mathrm{OCH}_{3}\right)\) and ethanol \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}\right)\) are isomers, but \(\mathrm{CH}_{3} \mathrm{OCH}_{3}\) has a \(\mathrm{pK}_{\mathrm{a}}\) of 40 and \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}\) has a \(\mathrm{pK}_{\mathrm{a}}\) of 16\. Why are these \(\mathrm{p} K_{\mathrm{a}}\) values so different?

Classify each species as a Lewis acid, a Bronsted-Lowry acid, both, or neither. a. \(\mathrm{H}_{3} \mathrm{O}^{+}\) b. \(\mathrm{Cl}_{3} \mathrm{C}^{+}\) c. \(\mathrm{BCl}_{3}\) d. \(\mathrm{BF}_{4}^{-}\)

Amino acids such as glycine are the building blocks of large molecules called proteins that give structure to muscle, tendon, hair, and nails. NCC(=O)O CC(=O)[O-] glycine zwitterion for a. Explain why glycine does not actually exist in the form with all atoms uncharged, but actually exists as a salt called a zwitterion. b. What product is formed when glycine is treated with concentrated HCl? c. What product is formed when glycine is treated with \(\mathrm{NaOH}\) ?