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NAROK UNIVERSITY COLLEGE (A CONSTITUENT COLLEGE OF MOI UNIVERSITY) UNIVERSITY EXAMINATIONS 2010/2011 SECOND YEAR SECOND SEMESTER EXAMINATION SCHOOL OF SCIENCE UNIVERSITY EXAMINATIONS FOR THE DEGREE OF BACHELOR OF SCIENCE AND BACHELOR OF EDUCATION (SCIENCE) COURSE CODE: PHY212 COURSE TITLE: ELECTRICITY AND MAGNETISM DATE: APRIL, 2011 TIME: 3 HOURS INSTRUCTIONS Answer Question ONE and any other TWO questions. o o o o o o o USEFUL DATA Planck constant ; h = 6.626 x 10 Js Avogadro constant; NA = 6.023 x 1023mol-1 Ln x = 2.303 log x 0oC = 273 K R = 8.314 JK-1Mol-1 = 8.205 x 10-2 l atm K-1 Mol-1 K = 1.381 x 10-23JK-1 1 atm = 1.013 x 105 Nm-2 -34 QUESTION ONE: a) Briefly explain each of the following terms: (i) Specific heat capacity (1 mk) (ii) Law of corresponding states (1 mk) (iii) Intensive property (2 mks) (iv) State function (2 mks) Page 1 of 3 [40 marks] [2] (v) b) (i) (ii) Critical temperature Briefly explain the two assumptions made when explaining the ideal behavior of gases (2 mks) Two moles of Ammonia gas occupy a volume of 5 x 10-3m3 at 300K. Calculate the pressure exerted in NM-2 using: I ideal gas equation (2 mks) II Van der Waal’s equation (6 mks) Given: c) (i) (ii) d) (2mks) a = 0.417 Nm4 Mol-2 b = 0.037 x 10-3 m3mol-1 Sketch a well labeled diagram to illustrate the isothermal reversible compression of a gas assuming ideal behavior. On the diagram indicate by shading the work done on the system. ( 4mks) iss the work in (i) above “positive” or negative work? Explain. ( 1 mk) 11.2 x 10-3 m3 of a certain gas at STP requires 104.6 J to raise its temperature by 10o degree. (i ) Calculate CV for the gas (3 mks) (ii) Assuming that the vibrational modes are inactive, what can be concluded about the structure of the gas molecule? (2 mks) e) For a diatomic molecule at 27oC, calculate: (i) Average molar energy, ET (ii) Heat capacity at constant volume (CV) (iii) Heat capacity at constant pressure (CP) f) (i) (ii) (2 mks) ( 3 mks) (2 mks) State Hess’s law of constant heat summation. (2 mks) Explain the meaning of heat of neutralization of a base. (2 mks) QUESTION TWO: [15 marks] a) Briefly explain the following terms: (i) Reversible process (ii) Isothermal process (2 mks) ( 1 mk) b) Two modes of oxygen gas at 300K and 20 atm pressure expands to 4 atm pressure. Assuming ideal behavior, calculate: ΔE, ΔH, W and W. QUESTION THREE: [15 marks] QUESTION FOUR: [15 marks] Page 2 of 3 The End Page 3 of 3