34. Consider the following compounds and formulas . (Note: The for- mulas are written in such a way as to give you an idea of the structure.) ethanol: CH_(3)CH_(2)OH dimethyl ether: CH_(3)OCH_(3) propane: CH_(3)CH_(2)CH_(3) The boiling points of these compounds are (in no particular order) -42.1^circ C,-23^circ C and 78.5^circ C . Match the boiling points to the correct compounds. __ 35. In each of the following groups of substances , pick the one that has the given property . Justify your answer. a. highest boiling point : HBr. Kr, or Cl_(2) b. highest freezing point: H_(2)O,NaCl .or HF c. lowest vapor pressure at 25^circ C:Cl_(2),Br_(2) .or I_(2) d. lowest freezing point: N_(2),CO . or CO_(2) e. lowest boiling point: CH_(4),CH_(3)CH_(3) . or CH_(3)CH_(2)CH_(3) f. highest boiling point: HF,HCl .or HBr

34. The boiling points of the compounds are as follows:<br />- Ethanol: $78.5^{\circ }C$<br />- Dimethyl ether: $-23^{\circ }C$<br />- Propane: $-42.1^{\circ }C$<br /><br />Therefore, the correct matches are:<br />- Ethanol: $78.5^{\circ }C$<br />- Dimethyl ether: $-23^{\circ }C$<br />- Propane: $-42.1^{\circ }C$<br /><br />35. <br />a. The correct answer is HBr. This is because HBr is a polar molecule due to the difference in electronegativity between hydrogen and bromine, which results in stronger intermolecular forces compared to Kr and $Cl_{2}$, leading to a higher boiling point.<br /><br />b. The correct answer is $H_{2}O$. Water has a high boiling point due to its strong hydrogen bonding between the molecules, which requires more energy to break.<br /><br />c. The correct answer is $I_{2}$. Among the given options, $I_{2}$ has the lowest vapor pressure at $25^{\circ }C$ because it has the weakest intermolecular forces, resulting in fewer molecules escaping into the vapor phase.<br /><br />d. The correct answer is $N_{2}$. Nitrogen has the lowest freezing point among the given options because it is a nonpolar molecule with weak van der Waals forces, making it easier to liquefy.<br /><br />e. The correct answer is $CH_{4}$. Methane has the lowest boiling point among the given options because it is a nonpolar molecule with weak van der Waals forces, resulting in lower intermolecular attractions.<br /><br />f. The correct answer is $HBr$. Among the given options, $HBr$ has the highest boiling point due to its stronger dipole-dipole interactions compared to $HF$ and $HCl$.