AP Chemistry/Gases

Kinetic Molecular Theory

Ideal gases don't exist, but if they did, they would fit the following descriptions:

• Full of tiny particles that are far apart
• Neither attract nor repel each other
• Are constantly and randomly moving, creating pressure
• Do not lose energy when colliding.

Pressure

Pressure is measured with a barometer (for atmospheric pressure) or a manometer (for sealed containers of gases).

General Chemistry/Gas Laws

Avogadro's Law

One mole of gas particles at STP takes up 22.4L

Ideal Gas Equation

PV=nRT, where R = 0.821 L*atm/K*mol = ideal gas constant. Note how if P is in atm, V is in L, n is in moles, and T is in Kelvin, the units cancel out.

Remember that these gas laws only work in Kelvin.

Graham's Law

For every x times heavier a gas is, it travels $\sqrt{x}$ times slower:

$\frac{v_2}{v_1}=\sqrt{\frac{M{M}_1}{M{M}_2}}$

Non-Ideal Gases

When gases are polar, massive, at high pressure and low temperature, they do not behave like ideal gases. They may even condense into liquids or freeze into solids.