HP 48gII Graphing, 50g Graphing manual Real Gas Law 5, Real Gas State Change 5

Equations:

T	= --------		2				P
------		2-	-----
T0	2 +		(	k – 1	) ⋅	M	P0
							1
							-----------
					ρ	=	 T  k – 1
				ρ----0--			 T----0-- 

k

-----------

= --T----  k – 1

 T0 

k + 1

-----------------------

A

1

⋅



2

⋅



k – 1

⋅ M

2   2

⋅ (k – 1)

-----

=

M----



k-----+-----1-



1 +

-----2------

 

At

Example:

Given: k=2, M=.9, T0=26.85_°C, T=373.15_K, ρ0=100_kg/m^3, P0=100_kPa, A=1_cm^2.

Solution: P=464.1152_kPa, At=0.9928_cm^2, ρ=215.4333_kg/m^3.

Real Gas Law (5, 6)

These equations adapt the ideal gas law to emulate realgas behavior. (See “ZFACTOR” in Chapter 3.)

Equations:

P ⋅ V = n ⋅ Z ⋅ R ⋅ T m = n ⋅ MW

Example:

Given: Pc=48_atm, Tc=298_K, P=5_kPa, V=10_1, MW=64_g/gmol, T=75_°C.

Solution: n=0.0173_gmol, m=1.1057E–3_kg.

Real Gas State Change (5, 7)

This equation adapts the ideal gas statechange equ ation to emulate realgas behavior. (See “ZFACTOR” in Chapter 3.)

Equation:

Pf ⋅ Vf	=	Pi ⋅ Vi
----------------Zf ⋅ Tf		---------------Zi ⋅ Ti

Example:

Given: Pc=48_atm, Pi=100_kPa, Pf=50_kPa, Ti=75_°C, Tc=298_K, Vi=10_1, Tf=250_°C. (Remember Zf and Zi are automatically calculated using these variables)

Solution: Vf=30.1703_l.

Equation Reference 527