Chemical Equilibrium Lab Report

Chemical equilibrium is a state of balance within a system of chemical reactions. Equilibrium in chemistry is achieved when substances are produced and broken down at the same rate and thus, the number of molecules of each substances becomes constant. Thermodynamics is a branch of physical science that involves the relationship between heat and other forms of energy (Energy, Enthalpy, and the First Law of Thermodynamics). There is a more specific area of thermodynamics that explicitly pertains to chemical reactions. The Gibbs free energy (ΔG°) is a chemical variable that expresses the balance between thermodynamic properties, known as enthalpy and entropy. Enthalpy is the heat absorbed or releases from a system and entropy is the measurement
Once the second 100 mL beaker reached 80°C and this was determined based on the glass thermometer. This heated solution was then poured immediately into the vacuum filtration system. The vacuum filtration system was set-up and ran identical to the experiment listed above. 10 mL of the 80°C saturated calcium hydroxide solution was measured using a 10 mL graduated cylinder. The 10 mL of the 80°C saturated calcium hydroxide solution was transferred to a 500 mL beaker from the 10 mL graduated cylinder. A stir bar was placed into the 500 mL beaker and the rest of the procedure was performed identical to the above experiment. The concentration of calcium hydroxide was then calculated. Using the known concentrations of hydrochloric acid and calcium hydroxide, the equilibrium constant was calculated. Lastly, the Gibbs free energy was calculated. Sample calculations can be seen in the Data section of this report. The ΔG values and corresponding temperatures were graphed and a line of best fit was added to determine the enthalpy and entropy of calcium hydroxide. This graph is displayed in the Observations, Results and Discussion section of this