Atmospheric Pressure: Gases exert pressure on their surroundings due to the force of gas molecules striking surfaces. The atmosphere (mainly N2, O2, Ar, CO2, Ne, He, CH4) exerts atmospheric pressure on Earth, measured using a barometer (standard pressure = 760 mmHg).

Units of Pressure: Common units include mmHg, torr, atm, Pa, and psi. Conversion: 760 mmHg=1 atm=101325 Pa=14.7 psi

Boyle's Law (Constant T): Pressure and volume are inversely proportional. P1V1=P2V2

Charles' Law (Constant P): Volume and temperature (in Kelvin) are directly proportional. V1T1=V2T2

Avogadro's Law (Constant T, P): Volume and moles of gas are directly proportional. V1n1=V2n2

Combined Gas Law: Relates pressure, volume, and temperature for a fixed amount of gas. P1V1T2=P2V2T1

Ideal Gas Law: Relates pressure, volume, temperature, and moles of gas. PV=nRT where R = 0.0821 L·atm/(K·mol).

Problem Solving: Use the appropriate law based on which variables are held constant or changing. Convert all temperatures to Kelvin and ensure units are consistent.

Sample Calculations: Example problems demonstrate how to use the gas laws to solve for unknowns such as volume, pressure, or moles, given the other variables.

Conceptual Understanding: Gas laws describe the relationships between physical properties of gases and are foundational for understanding gas behavior in various conditions.