BSc Chemistry SEM V 2018 19 2018-19 Chemistry Organic Chemistry Question Paper - Mumbai University | munotes

Questions asked in this paper

• 1. Please check whether you have received the right question paper

1. Q2 All questions are Compulsory
2. Q3 Figures to the right indicates full marks
3. Q4 Use of logtables/non-programmable calculator is permitted Answer any Four of the following
   • (A) a) Discuss the Bac* mechanism of hydrolysis of esters 3
   • b) Distinguish between transition state and intermediate 2
   • (B) a) Discuss the stereochemistry of NGP with a suitable example 3
   • b) Complete the following reaction and name the reaction involved: 2
   • (C) a)Explain with mechanism pyrolysis of acetates. 3
   • b) Explain chelotropic reaction with an example 2
   • (D) are electrocyclic and sigmatropic reactions? Explain with examples 3
   • b) Complete the following and name the reaction: 2
   • (E) a)Explain Intersystem crossing and electronic excitation process with the help 3 and labelled Jablonski diagram. Which out of the above two transitions is forbidden?
   • b) Explain with mechanism Di-m methane rearrangement 2
   • (F) a) Explain Norrish type Il reaction of 2-Pentanone 3
   • b) Write a note on photosensitization reaction. 2
4. Q2 Answer any four of the following
   • (A). Explain the optical isomerism in cummulenes with even no of double bonds (Allenes) 5
   • (B) a) State whether the following compounds are optically active or optically inactive. 3 Justify your answer
   • b) Define centre of symmetry with an example 2
   • (C) Give the Bischler-Napieralski reaction for the preparation of Write the 5 reaction of with n-Butyl lithium
   • (D) Convert Pyridine to Pyridine-N-oxide. Draw the resonating structures of Pyridine-N- 5 oxide. What is its action on 1) and 2) in Lig.NH3
   • (E) Complete the following reactions 5
   • (F) What are Agrochemicals? How are they classified? Give two advantages of it. Writethe 5 synthesis of Endosulfan
5. Q3 Answer any four of the following
   • (A) Explain the following terms with suitable examples: 5
   • (B) Write the structure of the following compounds: 5
   • (C) 1.0g of benzoic acid acid on esterification gave 1.25g of ethyl benzoate. Determine the 5 theoretical yield and percentage yield
   • (D) Design synthesis of the following compounds: 5
   • (E) What is the significance of atom economy? Calculate the % atom economy in the 5
   • (F) Explain the use of the following in green chemistry 5
6. Q4 Answer any four of the following
   • (A) Give analytical evidence to prove the following: 5
   • a) Citral is aldehyde
   • b) Citral is an acyclic monoterpenoid
   • (B) Discuss Hofmann’s exhaustive methylation and degradation of an alkaloid containing 5 Pyridine ring. What conclusions can you draw? Give the synthesis of : 5
   • a) Nicotine from Nicotinic acid
   • b) Adrenaline from protocatechuic aldehyde
   • (D) Discuss: 5
   • a) classification of terpenoids isomerism in citral
   • (E) Explain chromophore-auxochrome interaction in uv-visible spectroscopy with suitable 5
   • (F) Explain the significance of isotopic peaks in mass spectroscopy. Give the mass spectral 5 fragmentation of Propanone
7. Q5 (A) Select the correct answer and fill in the blanks (any Five) 5 marks
   • a) Cope elimination is observed in
   • b) All nucleophiles are undergoes electrocyclic reaction to form
   • d) attacks
   • i) one reaction involves pyrolysis of xanthate esters
   • f) | Phosphorescence involves the transition of to
   • i) singlet to singlet ii) triplet to triplet iii) singlet to triplet
   • g) Conversion of Allyl benzene to Phenyl cyclopropane is an example of
   • h) reacts with isopropyl alcohol in presence of light to form benzpinacol is an exampe of reaction
   • (B) State whether the following are True or False (any Five) 5 Cummulenes with even no of double bonds and unsymmetrical substitutions at terminal carbons will not show optical isomerism cyclobutane is chiral
   • c) Gibberelins belong to the class of Plant Growth Regulators Active component of neem oil is Azadirachtin cyclopropane is optically active
   • f) belong to the class of rodenticide Fungistatics kill the fungi
   • h) DDT and BHC belong to the class of Insecticides
   • (C) Give the IUPAC name of any five of the following compounds: 5
   • (D) State whether the following are True or False (any Five) 5
   • a) transitions occur at shorter wavelengths than transitions
   • c) spectroscopy, a molecular ion is a carbon radical
   • d) Inamolecule of citral the two olefinic double bonds are conjugated
   • f) is a pyrrole-piperidine alkaloid
   • g) The main function of adrenaline is to increase the blood pressure

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