SCH 3U1
THE IDEAL GAS LAW
The volume of a gas depends upon:
V  1/P (Boyle’s Law)
V  T (Charles’ Law)
V  n (Avogaro’s Law, n1/n2 = V1/V2)
If these factors are placed into an equation, a constant of
proportionality is needed. Thus, PV = nRT is the ideal gas law.
(Recall: an ideal gas assumes there are no forces between the
gas particles.)
P is pressure in kPa, mmHg, torr or atm
V is volume in L
n is moles
R is the gas constant in (L x *pressure unit)/(mol x K)
T is temperature in K
*using kPa - 8.314; using mmHg - 62.4; using atm - 0.0821
Example 1 – At STP, calculate the volume of 1.00 mol of a gas.
Given:
P = _______kPa
V=x
n = ____ mol
R = ______ L x kPa/mol x K
T = ____ K
PV = nRT
V = _________
V=
)
V = _____ L - THIS IS THE MOLAR VOLUME FOR ALL GASES AT STP.
Textbook Problems: # 12-15 on p.487-8