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
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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)
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[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]
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The End
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