CHT205 Chemical Engineering Thermodynamics-I
Tutorial-3
1. An insulated container filled with 25 kg of water at 20◦ C is fitted with
a stirrer. The stirrer is made to turn by gravity acting on a weight
of mass 25 kg. The weight falls slowly through a distance of 5 m.
Determine:
(a)
(b)
(c)
(d)
the amount of work done on water
change in internal energy of water
final temperature of water
amount of heat that must be removed from water to return to its
initial temperature
2. One model of a gas in a closed system undergoes four step thermodynamic cycle. Use the data given in the following table to determine
numerical values of missing quantities.
Step
∆U (J)
a→b
-200
b→c
?
c→d
?
d→a
4700
a→b→c→d→a
?
Q (J) W (J)
?
-6000
-3800
?
-800
300
?
?
?
-1400
3. One kg of liquid water at 25◦ C
(a) experiences a temperature rise of 1◦ C. What is ∆U in kJ?
(b) experiences a change in elevation ∆z with the change in potential
energy same as ∆U in part a. What is ∆z?
(c) is accelerated from rest to velocity v. Change in kinetic energy is
same as ∆U in part a. What is v?
4. (a) Heat in the amount of 7.5 kJ is added to a closed system while its
internal energy decreases by 12 kJ. How much energy is transferred
as work?
(b) For a process causing same change of state but work as zero, how
much heat is transferred?
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