HP (Hewlett-Packard) HP 33s Calculator User Manual


 
7–4 Solving Equations
File name 33s-English-Manual-040130-Publication(Edition 2).doc Page : 388
Printed Date : 2004/1/30 Size : 13.7 x 21.2 cm
Example: Solving the Ideal Gas Law Equation.
The Ideal Gas Law describes the relationship between pressure, volume,
temperature, and the amount (moles) of an ideal gas:
P
×
V = N
×
R
×
T
where
P is pressure (in atmospheres or N/m
2
), V is volume (in liters), N is the
number of moles of gas,
R is the universal gas constant (0.0821 liter–atm/mole–K
or 8.314 J/mole–K), and T is temperature (Kelvins: K=°C + 273.1).
Enter the equation:
Keys: Display: Description:
º
d
h
P
¸

Selects Equation mode
and starts the equation.
h
V
º
¢
h
N
¸
h
R
¸
h
T

Ï

Terminates and displays
the equation.
º
Î


Checksum and length.
A 2–liter bottle contains 0.005 moles of carbon dioxide gas at 24°C. Assuming
that the gas behaves as an ideal gas, calculate its pressure. Since Equation mode
is turned on and the desired equation is already in the display, you can start
solving for
P:
Keys: Display: Description:
Û
P

value
Solves for P; prompts for
V.
2
¥

value
Stores 2 in V; prompts fo
r
N.
.005
¥

value
Stores .005 in N;
prompts for
R.
.0821
¥

value
Stores .0821 in R;
prompts for
T.
24
Ï
273.1
Ù


Calculates T (Kelvins).