HP -225 Owner's Manual page 109

.0821 T?value Stores R, prompts for
T.
24 2731 T=297.1000 Calculates and stores T
P=0.0610 (K), calculates P (atm.)
Example: Density of a Gas. A 5-liter flask contains nitrogen gas.
The pressure is 0.05 atmospheres when the temperature is 18°C. Cal-
culate the gas density.
Step 1: Calculate N.
Keys: Display: Description:
B(soLvE] {N} P2value Selects N, prompts for
P.
.05 V2value Stores P, prompts for
V.
5 R?value Stores V, prompts for
R.
.0821 T?value Stores R, prompts for
T.
18 273.1 T=291.1000 Calculates and stores
N=8.8185 T, calculates N.
Step 2: Calculate the mass (mass = N X molecular weight; the mo
lecular weight of nitrogen is 28).
(x] 28 (=] 0.2929 Calculates the mass.
Step 3: Calculate the density (density = mass <+ volume):
(£] V (=] 8.0586 Calculates the density.
7: The Equation Library 101