1. Kinetic Molecular Theory-KMT
Students will be able to solve for gases under other conditions besides STP.
Kinetic Molecular Theory-KMT
Benchmark 4 Gases
Chemistry

2. Kinetic-Molecular Theory
KMT explains the assumptions that all gas laws follow.
What is an “ideal gas”?

3. Main Tenets of Kinetic-Molecular Theory
Gas molecules are dimensionless points with no volume.

4. 2. Gas molecules move in straight line motion.
Figure: 10-22
Title:
Diffusion of a gas molecule.
Caption:
For clarity, no other gas molecules in the container are shown. The path of the molecule of interest begins at the dot. Each short segment of line represents travel between collisions. The blue arrow indicates the net distance traveled by the molecule.

5. 3. Collisions are perfectly elastic.

6. 4. Gas molecules do not attract or repel each other.
Figure: 10-26
Title:
The effect of intermolecular forces on gas pressure.
Caption:
The molecule that is about to strike the wall experiences attractive forces from nearby molecules, and its impact on the wall is thereby lessened. The lessened impact means the molecule exerts a lower-than-expected pressure on the wall. The attractive forces become significant only under high-pressure conditions, when the average distance between molecules is small.

7. Why are all gas laws based upon the ideal gas that does not exist?
Real gases behave like Ideal gases under moderate conditions.
What is moderate?
High temperature, enough to be a gas
Low pressure, still able to behave like gas molecules.

8. Ideal Gas Law

9. PV = nRT Ideal-Gas Equation Temp in Kelvin Pressure in atmospheres
Universal gas constant
L·atm
K·mole
Volume in Liters
moles

10. Calculate the volume occupied by 7.40 g of NH3 at STP.

11. Calculate the pressure of 1
Calculate the pressure of 1.82 moles of a gas in a 5143 mL container at 69.5˚C.