(7 pages) APRIL 2015 Time : Three hours Maximum : 75 marks SECTION A (10 2 = 20 marks) Answer any TEN questions, each in 30 words. 1. Define order of reaction. ÂøÚ i Áøμ Ö. 2. What is energy of activation? How does it explain the speed of a reaction? QͺÄöPõÒ BØÓÀ GßÓõÀ GßÚ? Ax J ÂøÚ ß ÁPzøu GÆÁõÖ ÂÍUSQÓx? 3. State Beer Lambert s law. º»õ ºm Âvø TÖP. 4. Define quantum yield. SÁõsh ÂøÍa\À Áøμ Ö. 5. Identify the point groups of the following : (a) O H 2 (b) NH 3
RÌUPõs ÁØÔß ÒÎz öuõsvø PshÔP : (A) H 2 O (B) NH 3 6. What is meant by symmetry operation? Write the symmetry operations of H 2 O molecule. ^ºø ö\ À õk GßÓõÀ GßÚ? ^ºø ö\ À õkpøí GÊxP. H 2 O»UTÔß 7. What is meant by a reversible cell? Give an example. «Ò ªßP» GßÓõÀ GßÚ? Kº Euõμn u P. 8. If the emf of a cell consisting of a quinhydrone electrode and a saturated calomel electrode is 0.2640 V at 25 C. What will be the ph of the solution? (Given : ECalomel = 0.2422 V and Eq = 0.6996V). S ß øíi μõß ªß øú ØÖ {øóäøó Põ» À ªß øúpøí öpõsh J ªßP»zvß emf ß v 25 C öá {ø» À 0.2640 V BS. A u Pøμ\¼ß ph v GßÚ? (uμ mkòíx : E Põ» À = 0.2422 V ØÖ E S ß øíi μõß = 0.6996 V). 9. State Ostwald dilution law. BìmÁõÀiß }ºzuÀ Âvø TÖP. 2
10. What are strong and weak electrolytes? Give an example for each. à ªS ØÖ Ã SøÓ ªß SÎPÒ GßÓõÀ GßÚ? AøÁ JÆöÁõßÔØS u»õ J Euõμn u P. 11. State Hittorf s rule. îmhõº Âvø TÖP. 12. Under what conditions does the rate of a reaction become equal to rate constant? G u { uøú À J ÂøÚ ß ÂøÚ ÁP Auß ÁP õô¼us \ õs? SECTION B (5 5 = 25 marks) Answer any FIVE questions, each in 200 words. 13. Derive the expression for the rate constant of a first order reaction. Bring out the relation between half life period and this rate constant. uà i ÂøÚ ß ÁP õô¼upõú \ ß õmøh Á Â. A u ÂøÚ ß Aøμ B²Ò Põ»zvØS Auß ÁP õô¼us Cøh õú öuõhºø öpõnºp. 3
14. Distinguish between physisorption and chemisorption. C Ø PÁºa] μ ØÖ Áv PÁºa] μ BQ ÁØÔØQøh õú ÁÖ õkpøí u P. 15. Construct the group multiplication table for H 2 O molecule and explain. H 2 O»UTÖÂß öuõsv ö UP AmhÁøn Pmhø zx ÂÍUSP. 16. For the reaction Zn + 2AgCl ZnCl2 + 2Ag. (Given : E = 1.105 V, 4 ( E / T ) 4.02 10 Volt deg 1 ) calculate P G and S of the reaction. Zn + 2AgCl ZnCl2 + 2Ag GßÓ ÂøÚ ß G ØÖ S BQ ÁØøÓ PnUQkP. (uμ mkòíx : E = 1.105 V, 4 ( E / T ) 4.02 10 ÁõÀm iq 1 ) P 17. State and explain Kohlraush s law. PõÀμõa Âvø TÔ ÂÍUSP. 4 [P.T.O.]
18. The emf the cell Ag, AgCl 0.1 M KCl // Sat NH4 NO3/0.1 M AgNO3, Ag is 0.44 V at 27 C. Calculate the solubility product and solubility of AgCl. Ag, AgCl, 0.1 M KCl // Sat NH4 NO3/0.1 M AgNO3, Ag GßÓ ªßP»zvß emf v 27 C öá {ø» À Auß 0.44 V BS. AgCl ß PøμvÓß ö UP ØÖ Pøμ² ußø BQ ÁØøÓ PnUQkP. 19. Derive Nernst equation for emf of a cell and write its importance. J ªßP»zvß emf UPõÚ ö ºßìm \ ß õmøh Á Â. Auß UQ zxázøu GÊxP. SECTION C (3 10 = 30 marks) Answer any THREE questions, each in 500 words. 20. (a) Discuss the Lindemann theory of unimolecular reaction. (b) Derive an expression for the rate constant of a second order reaction when the reactant concentrations are equal. (5 + 5) (A) J»UTÖ ÂøÚUPõÚ ¼smö ß öpõòøpø ÂÁõv. (B) ÂøÚ k ö õ ÒPÎß ö\ôä \ õp EÒÍ J C i ÂøÚ ß ÁP õô¼upõú \ ß õmøh Á Â. 5
21. (a) Differentiate thermal and photochemical reactions. (b) Derive the rate law for photochemical reaction between H2 and Cl2. (5 + 5) (A) öá ØÖ JÎ Áv ÂøÚPøÍ ÁÖ kzxp. (B) H2 ØÖ Cl2 UQøh õú JÎ ÁvÂøÚ ß ÂøÚ Âvø Á Â. 22. (a) Define point group. Assign point group for trans 1, 2 dichloroethylene. (b) List the symmetry operations of cis and trans H 2 O2 molecule. (5 + 5) (A) ÒÎ öuõsv Áøμ Ö. iμõßì 1, 2 øhs Íõ μõ Gzv¼ÝUPõÚ ÒÎ öuõsvø SÔ kp. (B) Jzu ØÖ Gvº Gvº H 2 O2»UTÖÂØPõÚ ^ºø ö\ À õkpøí mi ¼kP. 23. (a) What is meant by liquid junction potential? How it can be minimized? (b) What is meant by electrochemical series? Write its significance. (5 + 5) 6
(A) vμá \ v ªßÚÊzu GßÓõÀ GßÚ? Ax GÆÁõÖ SøÓUP kqóx? (B) ªß Áv Á ø\ GßÓõÀ GßÚ? Auß UQ zxázøu GÊxP. 24. (a) Discuss how transport number of an ion is determined by moving boundary method. (b) Write any three applications of conductance measurement. (5 + 5) (A) GÀø» PºÄ øó À J A Û ß PºÄ GsPøÍ GÆÁõÖ PshÔÁõ Gß øu ÂÁõv. (B) PhzxvÓß AÍÃmiß H uý ßÖ ßPøÍ GÊxP. 7