Physical Chemistry PDF Notes

## Physical Chemistry ### Chapter 1: "Physical Chemistry" - **Gases** - **Liquids** - **Thermochemistry** - **Electrochemistry** - **Chemical Kinetics** **Matter** - **Solid** - **Liquid** - **Gas** **Example: H2O** - **Solid** (Ice) - Molecules are tightly packed and do not move. - **Li...

## Physical Chemistry ### Chapter 1: "Physical Chemistry" - **Gases** - **Liquids** - **Thermochemistry** - **Electrochemistry** - **Chemical Kinetics** **Matter** - **Solid** - **Liquid** - **Gas** **Example: H2O** - **Solid** (Ice) - Molecules are tightly packed and do not move. - **Liquid** (Water) - Molecules are loosely packed and move freely. - **Gas** (Vapor) - Molecules are far apart and move rapidly. **Density** - Solid > Liquid > Gas **Gases are characterized by:** - Takes the shape of its container. - Gases are mixed to form a uniform mixture. - Gases are readily compressed. - Density of gas < Liquid < Solid **Gases are diffused in rapid and constant motion.** **Gas exerts pressure** **Force per unit area** - P = F/A **Pressure of gas** Force exerted on the wall of the container divided by the surface area of the container. **Pressure can be measured using:** - **Barometer** - **Manometer** **Barometer** - Measures temperature and pressure. - P = 760 mm Hg = 1 atm **Example**: 760 mm Hg --> 1 atm 520 mm Hg --> X atm X = 520/760 = 0,68 atm **Manometer** - Used to measure the pressure of a gas. **Gases Laws** - **Boyle's Law:** - At constant temperature, the volume of a gas is inversely proportional to the pressure. - V α 1/P - V = K/P - K = V.P - V1.P1 = V2.P2 = V3.P₃ = ... = K - **Charles's Law:** - At constant pressure, the volume of a gas increases directly with temperature. - V α T - V = K.T - V1/T1 = V2/T2 = K - **Amonton's Law:** - At constant volume, the pressure of a gas increases with increasing temperature. - P α T - P = K.T - **Avogadro's Law:** - At constant temperature and pressure, the volume of a gas is directly proportional to the number of moles of gas. - V α n - V = K.n ## Chapter 2: "Physical Chemistry" **Ideal Gas Law** - Ideal gas law combines **Boyle's law**, **Charles's law** and **Avogadro's law**. - PV = nRT - P = pressure (atm) - V = volume (L) - n = number of moles - R = ideal gas constant (0,082 J) - T = temperature (K) - T = 0 °C = 273 K - 1 mol = 22,4 L **Kinetic theory of gases** - PV = (1/3) m c² **Gay-Lussac's Law of Combining Volumes and Avogadro's Principle** - At constant temperature and pressure, equal volumes of gases contain equal numbers of molecules. - Example: H2 + Cl2 --> 2HCl - Number of moles of H2 = 1/2 number of moles of HCl. **Dalton's Law of Partial Pressure** - The total pressure of a mixture of gases that do not react with each other is equal to the sum of the partial pressures of all gases in the mixture. - Ptotal = PA + PB - **Mol fraction (X)** XA + XB + XC + ... = 1 - XA = PA / Ptotal - XB = PB / Ptotal - **Partial Pressure** - PA = XA.Ptotal - PB = XB.Ptotal