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2.33 The salt with the nonpolar hydrocarbon chains bonded to the nitrogen will be more soluble in hexane than ammonium chloride because hexane is a nonpolar solvent. 2.34 Like dissolves like. Both benzene and hexane are nonpolar compounds, and are miscible. Water is a polar compound. Therefore, benzene and water are immiscible. 2.35 The carboxylic acid is miscible with water because it is more polar and can act as a hydrogen bond donor and acceptor with water. The ester is less polar and can only act as a hydrogen bond acceptor. It is nearly insoluble in water. H H 2.36 H H-C C H C C H H H H C C H : C C-H H H H 2.37 Use Table 2.1 in the text to calculate total bond energies of compounds. The aldehyde has 4 C-H bonds, 1 C-C bond, and 1 C=O bond, giving it a total bond energy of 646 kcal/mol [4(98) + 81 +173]. The alcohol has 3 C-H bonds, 1 C=C bond, 1 C-O bond, and 1 O-H bond, giving it a total bond energy of 627 kcal/mol [3(98) + 145 + 79 + 109). Therefore, the aldehyde is more stable. 2.38 + H-H CH₃-CH₃ 537 kcal/mol 104 kcal/mol 669 kcal/mol The total bond energy of the product (669 kcal/mol) is larger than that of the reactants (537 + 104 = 641 kcal/mol). This means that the product is more stable than the reactants and the reaction is energetically favorable. 2.39 Draw all the isomers (three) of C₅H₁₂. Then draw the possible C₅H₁₁ CI isomers that could be produced from each. Only the straight chain isomer of C₅H₁₂ can produce three isomers of 23