BSc Chemistry SEM II 2016 17 2016-17 Chemistry Paper II Question Paper - Mumbai University | munotes

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1. Q2 Answers to the same questions must be written together
2. Q3 Figures to the right indicate full marks
3. Q4 The use of log table/non-programmable calculator is allowed
4. Q1 A_ Select the correct option and complete the following statements. 12 marks
   • i. A plane whose intercepts in crystallographic axes are a:oob: its Miller indices are
   • ii. Sodium chloride crystal possesses elements of symmetry
   • iii. LS the POH of 0.1M NaOH
   • iv. The energy of that of ultraviolet radiations
   • a) less than
   • b) greater than
   • v. The molecular shape of PCls
   • a) triangular planar
   • b) pentagonal
   • vi. species is isoelectronic with Vil. Oxidation state of Chromium in is
   • a) Znis reduced
   • b) Zn is oxidized
   • c) Chlorine is oxidized
   • Q.P. Code :03733
   • ix. CONformer has maximum torsional strain
   • a) Eclipsed
   • b) Staggered
   • c) Skew
   • x. When a molecule experiences strain, its internal energy
   • a) decreases
   • b) increases
   • c) equalizes
   • xi. Cyclooctane has . Strain than cyclohexane due to torsional strain
   • a) lesser
   • b) greater
   • c) equal or lesser
   • xii. Cyclohexane has the highest . of all the alicyclic ring systems
   • a) stability
   • b) unstability
   • c) energy B whether the following statements are True or False : 03
   • i. Fluorescence involves the absorption of high energy radiation by a sample followed by the instantaneous emission of low energy radiation
   • ii. Greater the difference in electronegativity of the combining atoms, more polar is the
   • iii. C-C-C bond angle in cyclopropane is C Match the following columns. 05
   • i. Henderson’s equation for acid 1) 0.1nm
   • iii. Self oxidation and reduction 3) ortho, para directing
   • iv. Graphical representation of 4) disproportionation stability of different oxidation
5. Q6 meta directing and deactivating
6. Q2 A i. Derive an the acid dissociation constant of a weak monobasic acid, HA and for the base dissociation constant of a weak monoacidic base, BOH 5 marks
   • ii. Explain :
   • a) Buffer action 03
   • b) Buffer capacity
   • Q.P. Code :03733 A i. Define the term crystallography and state its three laws. 05
   • ii. What is emission spectroscopy ? 03 B i. A buffer solution of pH equal to 6.6 is to be prepared with 500 cm? of 0.08M solution of 05 a weak acid HA (Ka = 6 x Calculate the amount of the salt to be added to the buffer solution. The molar mass of the salt is 142
   • ii. Calculate the frequency, wave number and energy associated quantum of visible 03 light of (h = 6.626 x Js, c= 3.x m/s) B i. The dissociation constant of a weak monobasic acid is 2.6 x Calculate its degree of 05 dissociation and concentration of H* ions in 0.06M solution of acid
   • ii. What is the pH of a 0.25M solution of a weak monoacidic base, strychnine at 298 K? 03 C i. Deduce the expression for ionic product of water at 298 K. 02
   • ii. Define a buffer Give examples of C i. Explain pH scale in detail. 02
   • ii. Define the term : 02
   • a) Wave length of radiation
   • b) of radiation
   • i. Define the covalent bond. Explain its three characteristics. 04
   • ii. Illustrate with suitable examples, how.the covalent character is favoured by charge on 04 the ion and pseudo inert gas configuration A i. On the basis of Sidgwick Powell’s theory, predict and explain the shapes of the following 04 types of molecules :
   • ii. State and justify whether the following pairs of molecules are isoelectronic or not 04 B i. Balance the following question with stepwise explanation in acidic medium 04 Construct a Frost diagram from the following Latimer diagram (in aqueous acidic 04
   • Q.P. Code :03733 solution) and explain which is
   • a) the most stable oxidation state
   • b) the oxidation state having highest reduction potential B i. Explain the role of iodine as a redox agent with suitable examples. 04
   • ii. the Esystem for the titration of 50.0 cm? of 0.1M Fe(II) with 0.02M on 04 addition of (a) 25.0 cm? (b) 50.0. cm? and (c) 55.0 cm? solution of 0.02M at pH = C_ Explain the application of VSEPR theory for predicting shape and F —Xe -F bond angles 04 In XeFs [Atomic number of Xe = 54] Explain the application of VSEPR theory for predicting the shape and F bond 04 angles in IF7 [Atomic number of | = 53]
7. Q4 A i. Explain aromatic electrophilic substitution with mechanism. 5 marks
   • ii. Write Hammond’s postulate about transition states. 03 A i. Explain directing influence of group on electrophillic aromatic substitution. 05
   • ii. State the influence of the following groups on orientation of the incoming electrophile in 03 B i. Explain how does group influence orientation and reactivity for electrophilic 05 substitution.in nitrobenezene? What Illustrate with two examples. 03 B i. What is Friedel Crafts acylation? Explain the mechanism of the reaction and give one 05
   • Q.P. Code :03733
   • ii. What is Huckel’s rule? Explain how benezene and phenanthrene obey this rule. 03 Explain the aromaticity of the following :- 04
   • i. Furan With suitable examples explain Baeyers strain and transnnular strain in cycloalkanes. 04
8. Q5 any FOUR of the following : Explain in detail “Common lon Effect”. 05 Find the Miller indices of the planes whose intercepts on crystallographic axes are 05 C On the basis of Lewis concept of covalent bonding, explain double and triple bonding in 05 D Find the oxidation number of Manganese in and Chlorine in 05 E Draw various conformers of cyclohexane and explain their relative stabilities. Explain 05 flipping in cyclohexane F Explain with mechanism :- “sulphonation of benezene”. 05

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