(i)Draw the structures of the following compounds: a) Spiro [2.4]heptane b) Bicycto [2.2.2] ryclo octane c) Hexane dioic acid d) 4-oxobutanoic acid e) Ethanoic anhydride [5]
(ii)Justify the following statement: a) Dimethyl amine is stronger base than methyl amine which is stlronger than ammonia b) phenol is stronger than ethanol c) m - chloro-benzoic acid is a stronger acid than p - chloro-benzoic acid d) Pyrrole is a weaker base than pyridine [10]
(iii)Draw the resonance structures of the following compounds: (a) CH2=CH-CH3 (b) CH3=CH-O-CH3 (c) CH3-N=N=N (d) CH2=CH-C=N (e) CHg-C-CH2-C-OC2H5 [5]
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Q. 2
(i)Methanol is a good solvent for UV but not for IR Spectroscopy. Explain the fact. [5]
(ii)Briefly describe the basic difference between Beer's and Lambert's laws of absorption of light. [5]
(iii)Explain the working of double beam IR instrument with special discussion on the formation of a solution and recording of absorbance. [10]
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Q. 3
(a)Illustrate the difference between the following with examples: i, ConjugationandHyperconjugation. ii. Mesomeric Effect and Inductive Effect. iii. Chromophore and Auxochrome. iv. Electromeric Effectand.Resonance Effect. [17]
(b)Why esters have low boiling points than their corresponding acids? [3]
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Q. 4
(a)Explain the principle of UV and IR Spectroscopy. [7]
(b)How would you distinguish between ethane ethylene and acetylene by IR spectroscopy? [6]
(c)Differentiate between Bathochromic Shift and Hypsochromic Shift. [5]
(d)What is the formula for absorbance of a substance in Electronic Spectroscopy? [2]
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Q. 5
(i)Explain the steps involved in the phenomenon of "Walden Inversion". [5]
(ii)Discuss the role of Nicol Prism for plane of polarized light. [5]
(iii)Sketch the energy profile diagram and shapes of boat, twist boat, half chair and chair conformations of cyclohexane. [10]
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Q. 6
(i)Differentiate between the following terms with the help of appropriate examples. [8]
(ii)Proteins exhibit a variety of coloured reactions, describe any four of these. [8]
(iii)Hydrogen bonding plays an important role in protein structure, prove it. [4]
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Q. 7
(a)What are Carbohydrates? Discuss their classification. [8]
(b)How do you differentiate between paper partition and adsorption paper chromatography? [6]
(c)Define Detergent. What are its types and how it is different from soap? [6]
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Q. 8
(a)Explain the difference between chain growth and step growth polymerization? [6]
(b)Write a brief note on the following: i, TLC ii. Functions of Lipids iii. PTFE and its applications iv. P-type and N-type Semiconductors [14]
The 2019 PMS Punjab Chemistry paper set by the PPSC. Question wording only; questions marked “Not yet checked” have not been compared with the official paper yet.
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