Today in class Mrs. Friedmann checked the gas variables packets and then went over the pressure handout.

Class Notes:

Kinetic Molecular Theory (KMT)

1) The behavior of gases depends on the movement of gas particles

2) Temperature is a measure of the average kinetic energy of the gas particles

Two big points:

·         All molecules in a gas do not move at the same speed (even if there is only one kind of molecule).

·         When a gas is a mixture of molecules, the differences in speed are even greater. Large molar mass is slow. Small molar mass is fast. But the average is the same.

3) Assumptions:

·        No attractions between molecules

·         Molecules are infinitely small

·         Particles are in constant motion

·         Pressure comes from collisions with container walls

·         Deviations from this “ideal” are largest at very low temperatures and very high pressures

·         At STP (0 degrees Celsius and 1.0 atm) ideal works

4) Things that increase pressure:

·         More molecules (more collisions)

·         Smaller volume (more collisions)

·         Higher temperature (more collisions and greater force of collisions)

Homework:

Complete “Open and Closed Manometer Problems” worksheet.

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