Hydrazine \(\left(\mathrm{H}_{2} \mathrm{NNH}_{2}\right),\) hydrogen peroxide \((\mathrm{HOOH}),\) and water \(\left(\mathrm{H}_{2} \mathrm{O}\right)\) all have exceptionally high surface tensions compared with other substances of comparable molecular weights. (a) Draw the Lewis structures for these three compounds. (b) What structural property do these substances have in common, and how might that account for the high surface tensions?

First, we need to draw the Lewis structures for each of these compounds: 1. Hydrazine: \(\mathrm{H}_{2} \mathrm{NNH}_{2}\) 2. Hydrogen peroxide: \(\mathrm{HOOH}\) 3. Water: \(\mathrm{H}_{2} \mathrm{O}\) To draw the Lewis structures, we must consider each atom's valence electrons, placing them as shared pairs to form bonds or as lone pairs around atoms.

Next, we look at the Lewis structures we drew previously and identify the common structural property among hydrazine, hydrogen peroxide, and water. The common structural property in these compounds is that they all involve hydrogen bonded to highly electronegative atoms: nitrogen in hydrazine, oxygen in hydrogen peroxide, and oxygen in water.

Finally, we need to explain how the identified common structural property might account for the high surface tension of these substances. Surface tension is the result of cohesive forces between molecules in a liquid. Hydrogen bonding is a strong type of intermolecular force, which occurs in these compounds due to the presence of highly electronegative atoms (as identified in step 2) covalently bonded to hydrogen atoms. The strong hydrogen bonding intermolecular forces result in a higher surface tension in these substances compared to others with similar molecular weights that do not have hydrogen bonding. In conclusion, the high surface tension of hydrazine, hydrogen peroxide, and water can be attributed to the presence of hydrogen bonds between the highly electronegative atoms (N and O) and hydrogen atoms in their respective molecular structures.