Experiment 19 Equilibrium and Le Chatelier s Principle Chemistry 1220 136 October 5th 2013 Raffeal Bennett Purpose The purpose of this experiment was to see Le Chatelier s Principle in effect by exploring chemical equilibriums Additionally the purpose was to observe the effects of changes in concentration on a system in equilibrium and calculate the rate constant This final purpose was to determine if a reaction is endothermic or exothermic Procedure Refer to pages 61 63 of General Chemistry 1220 Laboratory Manual by The Ohio State University Department of Chemistry Hayden McNeil Publishing 2013 2014 Sample Calculations See attached sheet Discussion This experiment was broken up into a number of sections The first section was to simply observe the shifts of equilibrium in an aqueous Antimony Trichloride system As more and more water was added to the solution more precipitate formed turning the solution a milky white This transition was complete after 16 mL of water was added to the system Additionally the molarities at each increment can be calculated using m1v1 m2v2 The original molarity and volume was known along with the new volume By rearranging and solving the new molarity was calculated At the end 2mL of 6M HCL was added to the system This shifted the system back to its original form and made the precipitate disappear The same thing was done in the second part but different measuring instruments were used Then after determining the molarity of the SbCl3 and H and Cl at the point where the precipitate formed the equilibrium constant was calculated To do this the concentration of each ion were squared and multiplied together then divided by the concentration of SbCl3 This value came out to be 49 M 2S 1 Part C and D examined the chemical equation Co H2O 6 2 4CL CoCl2 6H20 HCL was added to 4M aqueous Co NO3 2 and the concentration of the chloride ions was calculated using the same method Once the solution became a dark blue color water was added to the solutions to show that the equilibrium shift can be reversed Once the water was added the solution started turning back to the original color This is because CoCl2 is blue and when Cl ions were added the equilibrium shifted to the right turning the solution blue The water then shifted the equilibrium back To determine if the reaction was exothermic or endothermic the solution was both heated and chilled When it was heated the solution turned the blue color and when it was cooled down it turned pink This means the reaction was endothermic because the heat pushes the equilibrium away Due to the fact that the solution was blue there was more CoCl2 which was a result of the heat This means the heat was on the reactant side of the equation making the entire reaction endothermic Conclusion In this experiment Le Chatelier s Principle was successfully illustrated and used to find the molarity of the different substances throughout a reaction Additionally the effects of temperature were investigated to see how the equilibrium was affected under high temperatures and lower temperature In this experiment the reaction was determined to be endothermic which means when heat was added the equilibrium was shifted to the right and when heat was taken away it was shifted to the left