Solubility Purpose: The purpose of this experiment is to determine the equilibrium concentrations for B₄O₅(OH)₄⁻². A graph will later be created with the axis labeled Kₛₚ and 1/T. The Kₛₚ value at each temperature will be determined by titrating B₄O₅(OH)₄⁻². Introduction: Solubility, S, is defined to be the maxim amount of solute that will dissolve in a given amount of solvent at a specific temperature. The equilibrium constant for the solubility of a sparingly salt is called solubility-product constant or Kₛₚ. Procedure: - Preparation of test tubes - Preparation of the saturated borax solution - Sampling the saturated borax solution - Titration of the borax sample solution - Repeat the above portions for all of the other borax sample - When done, all solutions ca be pored down the sink Data Analysis: ⁰C Temp. Initial Temp 1 Temp 2 45 47.2 45.3 45.1 35 37.7 35.2 35.1 25 33.3 25.1 24.9 15 22.4 15.7 15.3 5 10.1 5.5 5.1 ⁰C Amount of HCl Added in mL 45 10.5 35 10.8 25 7.2 15 9.4 5 6.3 Y = -0.0001x + 0.0036 Change In H Values -ΔH/R*R -ΔH = -0.0001*8.314 J/mol -ΔH = - 0.0008314 Change In G Values ΔG ⁰ = RTlnKₛₚ ΔG ⁰ = (8.314)(298.15)(0.993) ΔG ⁰ = 2,461.4 R= 8.314 J/mol-k T= 298.15 K lnKₛₚ = 0.993 Conclusion: As temperature increases, the more amount of of HCl will be required. This created a direct relationship between Temp and HCl. The equilibrium constant for Kₛₚ for the dissolution of the solution is related to the standard state free energy change. The entropy also increases as temperature increases.