1. Ideal Gas Law Marshall WW-P May 2013

2. Ideal Gas Law O Combined gas law assume a constant amount of gas (moles – (n)) O Could we calculate the # of moles in a fixed volume at a known temperature and pressure? O We need an expression that could accomplish this.

3. Ideal Gas Law How do we get this expression? O # of moles is directly proportional to the # of particles O Volume occupied by a gas at a specified temp. and pressure also depends on the # of particles. O What does this mean for the number of moles at it relates to volume? O They are directly proportional.

4. Ideal Gas Law

5. O What is the value of R? O If we know values for one set of conditions, a value for R can be calculated. O 1 mol of any gas occupies a volume of 22.4 L at STP which is 273K and 101.3kPa.

6. Ideal Gas Law

7. Ideal Gases vs. Real Gases O Ideal gases O Follow the gas laws at all conditions of pressure and temperature O No volume O No IMA’s O Is this realistic? O Real gases O Have volume O Have IMA’s (condensation) O at many temperatures and pressures behave as ideal gases except at low temperatures or high pressures.

8. Ideal Gases vs. Real Gases O Ratio of PV/nRT = 1 for ideal gases O IMA’s are strong PV/nRt <1 O Molecular volume can cause PV/nRT to be greater than 1