Define the following terms: Enthalpy, Lattice energy, Hydration energy, Entropy, Heat of combustion. Calculate the pH and pOH of a 2.3 x 10^-2 M HCl solution diluted to 100 mL.

Here are the solutions to your assignment questions. 1. Definitions: Enthalpy: A thermodynamic property representing the total heat content of a system at constant pressure. It is the sum of the system's internal energy and the product of its pressure and volume. Lattice energy: The energy required to completely separate one mole of a solid ionic compound into its gaseous ions. It is a measure of the strength of the electrostatic forces between ions in a crystal lattice. Hydration energy: The energy released when one mole of gaseous ions dissolves in water to form hydrated ions. It quantifies the attractive forces between ions and water molecules. Entropy: A thermodynamic property that measures the degree of randomness or disorder within a system. Systems tend to move towards states of higher entropy. Heat of combustion: The heat released when one mole of a substance undergoes complete combustion with oxygen under standard conditions. It is a specific type of enthalpy change. 2. Calculate the pH and pOH of each solution: a) 25.0 mL of 2.3 × 10^-2 M HCl, diluted to 100 mL Step 1: Calculate the initial moles of HCl. Moles of HCl = M_1 V_1 = (2.3 × 10^-2 mol/L) × (0.0250 L) = 5.75 × 10^-4 mol Step 2: Calculate the final concentration of HCl after dilution. M_2 = Moles of HClV_2 = 5.75 × 10^-4 mol0.100 L = 5.75 × 10^-3 M Since HCl is a strong acid, [H^+] = 5.75 × 10^-3 M. Step 3: Calculate pH. pH = -[H^+] = -(5.75 × 10^-3) = 2.24 Step 4: Calculate pOH. pOH = 14 - pH = 14 - 2.24 = 11.76 The pH is 2.24 and the pOH is 11.76. b) 5.0 mL of 1.87 M NaOH, diluted to 125 mL Step 1: Calculate the initial moles of NaOH. Moles of NaOH = M_1 V_1 = (1.87 mol/L) × (0.0050 L) = 9.35 × 10^-3 mol Step 2: Calculate the final concentration of NaOH after dilution. M_2 = Moles of NaOHV_