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/m2), 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:

HLP zº¾

Selects Equation mode

 

 

and starts the equation.

LV d



 

LN z



 

LR zLTº#/ºº!¾

 

‘

º#/ºº!

Terminates and displays

 

 

the equation.



/ 

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:

P

#@

Solves for P; prompts for

 

value

V.

2 g

@

Stores 2 in V; prompts for

 

value

N.

.005 g

@

Stores .005 in N;

 

value

prompts for R.
.0821 g

!@

Stores .0821 in R;

 

value

prompts for T.
24 ‘273.1›

!@

Calculates T (Kelvins).

 

 )

 

7–4Solving Equations