HP 48GII User Manual

5-26 Equation Reference
Example:
Given: T=16.85_°C, P=1_atm, V=25_1, MW=36_g/gmol.
Solution: n=1.0506_gmol, m=3.7820E-2_kg.
Ideal Gas State Change (5, 2)
Equation:
Pf Vf⋅
Tf
----------------
Pi Vi⋅
Ti
----------------
=
Example:
Given: Pi=1.5_kPa, Pf=1.5kPa, Vi=2_l, Ti=100_°C, Tf=373.15_K.
Solution: Vf=2_1.
Isothermal Expansion (5, 3)
These equations apply to an ideal gas.
Equations:
WnRTLN
Vf
Vi
------
⎝⎠
⎛⎞
⋅⋅⋅=mnMW⋅=
Example:
Given: Vi=2_l, Vf=125_l, T=300_°C, n=0.25_gmol, MW=64_g/gmol.
Solution: W=4926.4942_J, M=0.016_kg.
Polytropic Processes (5, 4)
These equations describe a reversible pressure-volume change of an ideal gas such that P ∗ V
n
is constant.
Special cases include isothermal processes (n=1), isentropic processes (n=k, the specific heat ratio), and
constant-pressure processes (n=0).
Equations:
Pf
Pi
-----
Vf
Vi
------
⎝⎠
⎛⎞
n–
=
Tf
Ti
------
Pf
Pi
-----
⎝⎠
⎛⎞
n1–
n
------------
=
Example:
Given: Pi=15_psi, Pf=35_psi, Vi=1_ft^3, Vf=0.50_ft^3, Ti=75_°F.
Solution: n=1.2224, Tf=164.1117_°F.
Isentropic Flow (5, 5)
The calculation differs at velocities below and above Mach 1. The Mach number is based on the speed of sound
in the compressible fluid.

HP 48GII Specifications

General

Battery type	CR2032
Type	Scientific
Form factor	Pocket

Weight and Dimensions

Weight	220 g
Dimensions (WxDxH)	184 x 87 x 23.5 mm