(Solved):   (2.0 pt) Write a detailed, stepwise mechanism for the following reaction. 2. (1.0 pt) ...

 

(2.0 pt) Write a detailed, stepwise mechanism for the following reaction. 2. (1.0 pt) Draw the most stable conformation of cis-1,4-dipropylcyclohexane and cis-1-ethyl-3-methylcyclohexane.. 3. (2.0 pt) Given the bond dissociation energies below (in \( \mathrm{kcal} / \mathrm{mol}) \), calculate the overall \( \Delta \mathrm{H}^{\circ} \) for the following reaction: \( \begin{array}{cl}\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CH}+\mathrm{Br} 2 & \left(\mathrm{CH}_{3}\right)_{3} \mathrm{CB} \\ \left(\mathrm{CH}_{3}\right)_{3} \mathrm{C}-\mathrm{H} & 91 \\ \left(\mathrm{CH}_{3}\right)_{3} \mathrm{C}-\mathrm{Br} & 65 \\ \mathrm{Br}-\mathrm{Br} & 46 \\ \mathrm{H}-\mathrm{Br} & 88 \\ \mathrm{CH}_{3}-\mathrm{Br} & 70\end{array} \) 4. (2 pt) Consider the reaction: \( \mathrm{CH}_{3} \mathrm{CH}_{2} \cdot+\mathrm{Br} 2 \rightarrow \mathrm{CH} 3 \mathrm{CH} 2 \mathrm{Br}+\mathrm{Br} \cdot \). Given that this reaction has activation energy of \( +6 \mathrm{kcal} / \mathrm{mol} \) and \( \mathrm{a}^{\circ} \mathrm{H}^{\circ} \) of \( -22 \) \( \mathrm{kcal} / \mathrm{mol} \), sketch a reaction-energy diagram for this reaction. Label the axes and show \( \mathrm{E}_{\mathrm{a}} \) and \( \Delta \mathrm{H}^{\circ} \) on your drawing. 5. (1 pt) In the hydrocarbon shown below, how many tertiary hydrogens are present?