Question

II. True/False. Write the word true or false by the following statements. (5) 1. A closed shell of re-electrons in an MO diagram of a cyclic compound indicates anti-aromaticity. 2. POCI, is a mild dehydrating agent for alcohols that follows an E2 mechanism. 3. For the re-system of benzene, there are six molecular orbitals with four different energy levels. 4. All meta directors in EAS reactions are strong electron withdrawing groups. 5. The catalyst in electrophilic aromatic substitution lowers the energy of the nonaromatic carbocation intermediate derived from benzene. III. Multiple choice. Choose the best answer(s). (16) 1. Which of the following substituents donates electron density to an aromatic ring through resonance? a. -CH3 b. NO C. -CO,CH3 d. -Br 2. Circle the oxidizing agent(s). hydroxide PCC NaBHA Jones TMSCI 3. Circle the compound with the highest expected boiling point? b. HOCH,CH,OCH CH OH CH,CH,OCH,CH3 C. CH3CH2CH2CH2OH

Answer 1

II) 1-False, 2-True, 3-True, 4-True. 5-False. Reasons are provided in the images below.

III) 1-d, 2- Jones, 3-a. Reasons are provided in the image below.

11) True / False False. Mo diagram of a 1. A closed shell of teketrons in an Mo diagram of a cyclic compound indicates anti-aromaticity. Reason: The number of electrons in the system is not mentioned which should be 4n for anti aromatic system, where no no. of forbitals) True 2. pochz is a mild dehydrating agent for alcohols in that follows €2 mechanism. True 3. For the IT system in Benzene, there are six mokanlar orbitals with four different energy levels. (Beason. To mo diagram of Benzene: ( - - - 4 ET! Y I – – 76 . - Y 1 T ---- V -Es . – Ez E 63 True 4. All meta directors in electrophilic aromatic substitution (EAS) reactions are strong electron with drawing groups.

aromatic ophiftic False frоm bетгая. 5. The n electroplittic substitution lowers the energy of the non aromatic carbocation intermediate derived from bei (Reason, the catalyst does not stabilizes the non ano matic intermediak, rather it activates the attacking electrophile, e.ge) Alchz is a catalyst in alkylation of benzene R-a thalcha St S- & Ia aldz activated electrophile - Aldu Rearomatisation - (Hel + A143) or - Häly

1. d. e- Br' donates electron density to an aromatic ring through resonance. X37 Atc, 2. 3. Jones' reagent is an oxidizing agent. [ Jones reagent = croz & H₂SO4 aqueous) It is generally med to oxidize 10 and zo alcohols Z novou or has highest expected boiling point. [ Reason. It has highest surface area which maximizes the van der Waals interaction and it has two - oth gro which provide maximuy mo. of #-bonding interactions]