Chapter 19

Can stereoisomers of molecules, such as cis and trans \(\mathrm{RCH}=\mathrm{CHR},\) also have optical isomers? (R may be any of the functional groups we have encountered in this textbook.) Explain your answer.

How many grams of liquid methanol must be combusted to raise the temperature of \(454 \mathrm{g}\) of water from \(20.0^{\circ} \mathrm{C}\) to \(50.0^{\circ} \mathrm{C} ?\) Assume that the transfer of heat to the water is \(100 \%\) efficient. How many grams of carbon dioxide are produced in this combustion reaction?

Raincoats "Waterproof" nylon garments have a coating to prevent water from penetrating the hydrophilic fibers. Which functional groups in the nylon molecule make it hydrophilic?

Draw the carbon-skeleton structure of the condensation polymer of \(\mathrm{H}_{2} \mathrm{N}\left(\mathrm{CH}_{2}\right)_{6} \mathrm{COOH} .\) How does this polymer compare with nylon- \(6 ?\)

The heats of combustion of two constitutional isomers are the same when estimated from average bond energies, but they are different when determined experimentally. Why?