Gas Laws and Principles Review

Flashcards covering key definitions and relationships in gas laws, density, and problem-solving strategies from the lecture.

Ideal Gas Law

A fundamental gas equation represented as PV=nRT, relating pressure, volume, moles, the gas constant, and temperature.

R-value (Gas Constant Units)

The specific units for the gas constant 'R' (liters atmospheres per mole Kelvin) that dictate the required units for other variables in the ideal gas law.

Volume Units for Ideal Gas Law

Must be in liters when using the R-value of liters atmospheres per mole Kelvin.

Pressure Units for Ideal Gas Law

Must be in atmospheres when using the R-value of liters atmospheres per mole Kelvin.

Temperature Units for Gas Laws

Always in Kelvin; requires adding 273 to a Celsius value.

Significant Figures in Gas Law Calculations

Determined by the measurement with the fewest significant figures, especially considering trailing zeros without a decimal.

Rounding in Multi-step Calculations

Keep all digits throughout intermediate steps and only apply significant figure rules to the final answer.

Pressure

Exerted by particles colliding with the walls of a container.

Density

The ratio of mass to volume (mass/volume).

Density Units for Gases

Typically expressed in grams per liter (g/L) because gases are less dense than liquids.

Molar Mass Calculation

Conversion from moles to grams using the atomic or molecular mass from the periodic table.

Diatomic Elements

Elements that exist naturally as molecules composed of two atoms (e.g., H2, O2, F2, Cl2, Br2, I2, N2, often remembered by 'Have No Fear Of Ice Cold Beverages').

Temperature (Kinetic Energy)

A measure of the average kinetic energy of the particles in a substance.

Boyle's Law

Describes the inverse relationship between pressure and volume; if pressure doubles, volume halves (at constant temperature and moles).

Combined Gas Law

An equation (P1V1/T1 = P2V2/T2) used to describe the relationship between pressure, volume, and temperature of a fixed amount of gas.

Gay-Lussac's Law

Describes the direct relationship between pressure and temperature; if temperature decreases, pressure also decreases (at constant volume and moles).

Rigid Container

A container that does not change its volume, implying constant volume in gas law problems.

Effect of Moles on Pressure

Fewer moles (or particles) in a container lead to less pressure due to fewer collisions with the container walls.

Problem-Solving Strategy (Complex Gas Law/Density Problems)

When faced with multiple unknown variables, making an assumption (e.g., 1 L volume, 1 mole) can simplify the problem and lead to a solution.