ECHE 311-SPRING 2015
Quiz 1
1. The general first-law equation for a mechanically reversible, nonflow process is given as:
d (nU )  dQ  Pd (nV )
(1)
If in addition the process occurs at constant volume, then the work is zero, and
dQ  d (nU )
Integration yields
Q  nU
Show that for mechanically reversible, constant-pressure, nonflow process, the
transferred equals to the enthalpy change of the system.
25 points
heat
2.
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Define the state function in thermodynamics.
Does a thermodynamic state reflects changes at the molecular (microscopic level).
Define the first law of thermodynamics.
The first law applies to
a. the system and surroundings
b. the system alone
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define and identify the extensive properties
define and identify the intensive properties
25 points
3. Define the differences between a constant temperature isothermal process and a reversible
adiabatic process
25 points
4. Explain the iteration procedure for calculation of T when To and Q or H are given in the
specific heat capacity equation.
Hint: Read the Chap “ Heat Effects” in your text book and my handouts.
25 points