Thermo Test 1
For liquid vapor mixture, the temperature and the pressure are known. The number of additional intensive, independent properties needed to fix the state of this system is _____ ?
1
1.8 J per degree C is equal to ____
1 J per degree F
50 C difference is equal to ______?
50 * 1.8 R difference
According to the 1st law, for all adiabatic processes between two specified states of a closed system, the net work done is______?
Always the same
Near ______, the ideal gas assumption for water vapor yields unacceptable errors.
Critical Point
Which one is NOT always correct for solids and liquids? (the density or specific volume is essentially constant during a process)
Delta H-liquid = Delta U-liquid
What pair of properties in the following are two independent intensive properties?
Density and pressure
A piston-cylinder device undergoes a process in which Change in U = U-final - U-initial = Q/2. This process results in system boundaries that --------?
Expand
All real gases deviate to some extent from the ideal gas law. For which of the following conditions are the deviations smallest?
High temperature and low pressures
Mechanical Energy refers to _____
Kinetic Energy + Potential Energy
Light-year has the dimension of __
Length
Critical point is the point at which _____?
Liquid vapor mixture is non-existant
Which one is NOT a mechanical form of work?
Magnetic work
Which of the following statements is the closest interpretation of the first law of thermodynamics for a closed system.
Net energy crossing the system boundary is the change in energy inside the system
An adiabatic process must be a process with _____?
No heat transfer
From textbook, whats the right procedure to determine compressibility factor Z for a gas with given T and P?
P-cr, T-cr --> P-r, T-r --> Z
For a system to be in thermodynamic equillibrium, which one of the following does not have to be the same everywhere?
Pressure
Which one of the following conclusions is NOT correct for cycles?
Q = Change in U
All of following properties have units, EXCEPT?
Reduced temperature
Which one is NOT an extensive property?
Specific Volume
In general which form of the same substance will hold the highest energy content?
Superheated Vapor
A system contains water at 2.00 MPa, 220 C. The phase of this water is _______.
Superheated Vapor (Temp Table A-4)
Compare T.f T.mixture and T.g at a given pressure for a liquid-vapor mixture?
T.f = T.mixutre = T.g
The compressed liquid properties strongly depend on ________?
Temperature
Boundary work, W-b, only exists in systems with moving boundaries, true or false.
True
For ideal gasses, u, h vary with temperature only, true or false.
True
Specific heat, C-p, is an intensive property, true or false.
True
Compare U.f, U.mixture, and U.g at a given temperature for a liquid-vapor mixture.
U.f < U.mixture < U.g
Which one is NOT a pure substance?
Water + Air
Which of the following is NOT an intensive property?
Work
Which one belongs to dynamic form of energy?
Work
In thermodynamics, positive work means ______ ?
Work done by a system
A container contains half liquid water by volume and half vapor by volume. Select the best estimate of the quality if the pressure is atmospheric?
X = 0.0006
Which one of the following statements is NOT correct about compressibility factor, Z?
Z reaches to unity when P reaches to P-critical
Boundary work requires?
a force acting on the boundary
In general, a system experiences no change in KE and PE during a process, this system must be ______
a stationary system
During melting process, a substance will _______ energy?
absorb
Which pair in the following has the closest properties at a given temperature?
compressed liquid and saturated liquid
The boundary work, W-b, is negative if the system experiences a _________ process.
compression
An ideal gas at a given state experiences following processes and eventually reaches to the same volume. For which case is the work done greater?
constant pressure process
What is the dominant heat transfer form in boiling a pot of water?
convection
Which of the following are NOT independent intensive properties?
density and specific volume
The properties of compressed liquid ________?
depend on temperature more than pressure
The First Law of thermodynamics states that _
energy can neither be created nor destroyed
At triple-point pressure and temperature, water _________?
exists in liquid-vapor-ice equilibrium
Which one of the following is NOT a point function
heat
Which case in the following has both volume flow rates and mass flow rates remain constant for an open system?
incompressible flow
The sum of all microscopic forms of energy is the ______ ?
internal energy
Which one of the following is NOT an intensive property?
internal energy
Which thermodynamic property in the following is the best measure of molecular activity on a substance?
internal energyy
A process with pressure held constant is so called an ____ process
isobaric
A process with Volume held constant is called an ______ process
isochoric
A hydraulic device is a device that uses liquids to transmit _____ equally from one point to another
pressure
The state of a thermodynamic system is always defined by its ___
properties
When the pressure of an ideal gas is doubled while the absolute temperature is halved, the volume is
quartered
We feel warm when we stay closer to a fireplace. This is due to ______ of the heat.
radiation
At constant temperature if P < P.sat the substance is in ___________ form
superheated vapor
All of the following statements about work done on or by a gas are true EXCEPT?
the differential of work is exact
What is the Zeoth law of thermodynamics about?
thermal equilibruim
Which one can best represent the "Flow Energy" for an open system?
u + Pv + V^2/2 +gz
The superheated vapor properties are ______ saturated vapor properties at a given Temperature?
very different from
All of the following statements about work done on or by a system are true EXCEPT:
work is possessed by the system
