Download measures of amount or size

MEASURES OF
AMOUNT OR
SIZE,STATE VARIABLE
MEMBERS OF GROUP NEWTON:
1)Yuganesh a/l Murugiah
2)Tan See Yean
3)Nazzira Md Zin
4)Nor Fatehah Kamaruddin
Three measures of amount or size
in common use:
• Mass,m
• Number of moles,n
• Total volume,Vt
The measures for a specific system are in direct porpotion to one
another.
Formulae of calculate:
• Number of moles, n = m
M
• Specific volume, Vt = mV
• Molar volume, Vt = nV
Vt = the size of a system
Definition Of Intensive &
Extensive thermodynamic variable
• An intensive quantity (also intensive variable) is a
physical quantity whose value does not depend on
the amount of the substance for which it is
measured.
• It is the counterpart of an extensive quantity. For
instance, the mass of an object is not a bulk
property, because it depends on the amount of that
substance being measured.
Examples:
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temperature
pressure
chemical potential
density
viscosity
electrical resistivity
melting point
boiling point
spectral absorption maxima (in solution)
flammability
specific energy
Extensive Variables
• An extensive quantity (also extensive variable or
extensive parameter) is a physical quantity, whose value
is proportional to the size of the system it describes.
Such a property can be expressed as the sum of the
quantities for the separate subsystems that compose the
entire system.
• Extensive quantities are the counterparts of intensive
quantities, which are intrinsic to a particular subsystem
and remain constant regardless of size. Dividing one
type of extensive quantity by a different type of
extensive quantity will in general give an intensive
quantity (mass divided by volume gives density).
Examples:
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mass
volume
entropy
energy
electrical resistance
texture
heat
The differences between intensive
and extensive properties
• An intensive property is independent of the amount of mass.
While the value of an extensive property varies directly with the
mass.
• Thus, if a quantity of matter in a given state is divided into two
equal parts, each part will have the same value of intensive property
as the original and half the value of the extensive property.
• Temperature, pressure, specific volume, and density are examples of
intensive properties.
• Mass and total volume are examples of extensive properties.
The End