ideal gas law pv = nrt brings together gas properties. can be derived from experiment and theory
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Ideal Gas Law
PV = nRTPV = nRTPV = nRTPV = nRTBrings together gas properties.
Can be derived from experiment and theory.
Ideal Gas Equation
P V = n R T
Universal Gas ConstantVolume
No. of moles
Temperature
Pressure
R = 0.0821 atm L / mol K
R = 8.314 kPa L / mol K
Kelter, Carr, Scott, Chemistry A Wolrd of Choices 1999, page 366
PV = nRT
P = pressureV = volumeT = temperature (Kelvin)n = number of molesR = gas constant
Standard Temperature and Pressure (STP)
T = 0 oC or 273 K
P = 1 atm = 101.3 kPa = 760 mm Hg
Solve for constant (R)
PV nT
= R
Substitute values:
(1 atm) (22.4 L) (1 mole)(273 K)
R = 0.0821 atm L / mol K or R = 8.31 kPa L / mol K
R = 0.0821 atm L mol K
Recall: 1 atm = 101.3 kPa
(101.3 kPa)
( 1 atm)= 8.31 kPa L mol K
1 mol = 22.4 L @ STP
Ideal Gas Law
What is the volume that 500 g of iodine will occupy under the conditions: Temp = 300oC and Pressure = 740 mm Hg?
Step 1) Write down given information. mass = 500 g iodine T = 300oC P = 740 mm Hg R = 0.0821 atm . L / mol . K
Step 2) Equation:
V =nRT
P
V (500 g)(0.0821 atm . L / mol . K)(300oC)
740 mm Hg=
Step 3) Solve for variable
Step 4) Substitute in numbers and solve
V =
What MISTAKES did we make in this problem?
PV = nRT
What mistakes did we make in this problem?
What is the volume that 500 g of iodine will occupy under the conditions: Temp = 300oC and Pressure = 740 mm Hg?
Step 1) Write down given information. mass = 500 g iodine Convert mass to gram;
recall iodine is diatomic (I2)x mol I2 = 500 g I2(1mol I2 / 254 g I2)
n = 1.9685 mol I2
T = 300oC Temperature must be converted to KelvinT = 300oC + 273
T = 573 K
P = 740 mm Hg Pressure needs to have same unit as R;therefore, convert pressure from mm Hg to atm.x atm = 740 mm Hg (1 atm / 760 mm Hg)
P = 0.8 atm
R = 0.0821 atm . L / mol . K
Ideal Gas Law
What is the volume that 500 g of iodine will occupy under the conditions: Temp = 300oC and Pressure = 740 mm Hg?
Step 1) Write down given information. mass = 500 g iodine
n = 1.9685 mol I2 T = 573 K (300oC) P = 0.9737 atm (740 mm Hg) R = 0.0821 atm . L / mol . K V = ? L
Step 2) Equation: PV = nRT
V =nRT
P
V (1.9685 mol)(0.0821 atm . L / mol . K)(573 K)
0.9737 atm=
Step 3) Solve for variable
Step 4) Substitute in numbers and solve
V = 95.1 L I2
Ideal Gas Law
What is the volume that 500 g of iodine will occupy under the conditions: Temp = 300oC and Pressure = 740 mm Hg?
Step 1) Write down given information. mass = 500 g iodine T = 300oC P = 740 mm Hg R = 0.0821 atm . L / mol . K
Step 2) Equation:
V =nRT
P
V (500 g)(0.0821 atm . L / mol . K)(300oC)
740 mm Hg=
Step 3) Solve for variable
Step 4) Substitute in numbers and solve
V =
What MISTAKES did we make in this problem?
PV = nRT