Messenger_creation_B4C53738-0E30-44FC-9737-DB7C334ECA2C.heic

# Chemical Principles ## The Properties of Gases ### 5.1 Gas Laws #### Boyle's Law Volume is inversely proportional to pressure $V \propto \frac{1}{P}$ $V = k \frac{1}{P}$ $PV = k$ $P_1V_1 = P_2V_2$ #### Charles's Law Volume is directly proportional to temperature $V \propto T$ $V = kT$...

# Chemical Principles ## The Properties of Gases ### 5.1 Gas Laws #### Boyle's Law Volume is inversely proportional to pressure $V \propto \frac{1}{P}$ $V = k \frac{1}{P}$ $PV = k$ $P_1V_1 = P_2V_2$ #### Charles's Law Volume is directly proportional to temperature $V \propto T$ $V = kT$ $\frac{V}{T} = k$ $\frac{V_1}{T_1} = \frac{V_2}{T_2}$ #### Avogadro's Law Volume is directly proportional to the number of moles $V \propto n$ $V = kn$ $\frac{V}{n} = k$ $\frac{V_1}{n_1} = \frac{V_2}{n_2}$ ### 5.2 The Ideal Gas Law #### Ideal Gas Law $PV = nRT$ $R = 0.08206 \frac{L \cdot atm}{mol \cdot K}$ $R = 8.314 \frac{J}{mol \cdot K}$ #### Density $d = \frac{m}{V} = \frac{PM}{RT}$ $M =$ molar mass ### 5.3 Gas Stoichiometry #### Molar Volume 1 mol of any gas at standard temperature and pressure (STP) occupies a volume of 22.4 L STP = 0°C and 1 atm ### 5.4 Dalton's Law of Partial Pressures #### Partial Pressure $P_A = X_A P_{total}$ $X_A = \frac{n_A}{n_{total}}$ ### 5.5 The Kinetic Molecular Theory of Gases 1. Gases are mostly empty space. 2. Gas particles are in constant, random motion. 3. All collisions between gas particles are perfectly elastic. 4. There are no attractive or repulsive forces between gas particles. 5. The average kinetic energy of gas particles is proportional to the absolute temperature. #### Root Mean Square Velocity $v_{rms} = \sqrt{\frac{3RT}{M}}$ ### 5.6 Real Gases: Deviations from Ideal Behavior #### van der Waals Equation $[P + a(\frac{n}{V})^2](V - nb) = nRT$ ## Chapter 6 ### Thermochemistry #### 6.1 The Nature of Energy ##### Energy The capacity to do work or produce heat. ##### Kinetic Energy The energy of motion. $KE = \frac{1}{2}mv^2$ ##### Potential Energy Energy possessed by virtue of position. ##### Law of Conservation of Energy Energy can be converted from one form to another but can neither be created nor destroyed. ##### State Function A property that is independent of the pathway. $\Delta E = E_{final} - E_{initial}$ #### 6.2 Enthalpy and Calorimetry ##### Enthalpy $H = E + PV$ $\Delta H = \Delta E + P\Delta V$ $\Delta H \approx$ heat for reactions at constant pressure $\Delta H = H_{products} - H_{reactants}$ ##### Calorimetry The amount of heat released or absorbed during a chemical reaction can be measured experimentally by calorimetry. $q = mc\Delta T$ $q =$ heat $m =$ mass $c =$ specific heat capacity $\Delta T =$ change in temperature ##### Heat Capacity of Calorimeter $q = C\Delta T$ $C$ = heat capacity of calorimeter ##### Constant-Pressure Calorimetry $\Delta H = q_p$ ##### Constant-Volume Calorimetry $\Delta E = q_v$ #### 6.3 Hess's Law ##### Hess's Law In going from a particular set of reactants to a particular set of products, the change in enthalpy is the same whether the reaction takes place in one step or in a series of steps. $\Delta H = \Sigma \Delta H_i$ #### 6.4 Standard Enthalpies of Formation ##### Standard Enthalpy of Formation The change in enthalpy that accompanies the formation of 1 mole of a compound from its elements with all substances in their standard states. $\Delta H_f°$ ##### Standard State 1 atm and 25°C ##### Standard Enthalpy Change $\Delta H° = \Sigma n_p\Delta H_f°(products) - \Sigma n_r\Delta H_f°(reactants)$