Table 1 the observation and results of part 1

This preview shows page 6 - 9 out of 11 pages.

Table 1 The Observation and Results of Part 1, demonstrates the effects caused by manipulating the system at equilibrium. These results were gathered by observation made when applying different changes to our system. The forward arrows represent that the reaction proceeded forward and produced more products until equilibrium was restored. The backward arrows represent the production of reactants until equilibrium is reached. More red is associated with an increase in rate of the forward reaction while less red is associated with an increase in rate of the reverse reaction. In the second part of the experiment, we wanted to determine the K value of our solution at two different temperatures. First, we set up dilutions of our solution and used a colorimeter to measure their absorbance values. Next, we prepared 7 test tubes with different initial concentrations of reactants to make our solution. Using the colorimeter, we measured each absorbance value at room temperature and than at 45 ℃. Two average K values were found for each solution at each temperature. Table 2 The Standard Solutions for Beer’s Law Plot : Absorption values increased as the concentration of [Fe(H 2 O) 5 (SCN)] 2 increased. A B C D E F G 1 Standard solution # Volume (mL) 1 M KSCN Volume (mL) 0.1 M HNO 3 Volume (mL) 1.0x10 -4 M Fe(NO 3 ) 3 Calculated Total Volume (mL) Calculated [Fe(H 2 O) 5 (SCN)] 2 + (M) Abs. 2 3 0 0 0 4 1 5.00 4.00 1.00 10.00 1.00E-05 0.081 5 2 5.00 3.50 1.50 10.00 1.50E-05 0.123 6 3 5.00 3.00 2.00 10.00 2.00E-05 0.168 7 4 5.00 2.50 2.50 10.00 2.50E-05 0.196 8 5 5.00 2.00 3.00 10.00 3.00E-05 0.236 Test Tube # Action Observation Conclusion ( J or ) 1 Control Light orange N/A 2 Add 1 mL of 0.1 M KSCN Dark red (more red) J 3 Add 1 mL of 0.1 M Fe(NO 3 ) 3 Dark orange (more red) J 4 5 drops of 0.1 M AgNO 3 White (less red) 5 Add to hot water bath Lighter orange (less red) 6 Add to ice water bath Medium orange (more red) J
Table 2 The Standard Solutions for Beer’s Law Plot, represents the preparation of the solutions needed to construct the Beer’s Law plot. Column G demonstrates the absorbance values that were found using a calorimeter. In each solution, KSCN was in excess to make sure that the reaction went to completion. This way the equilibrium concentration for [Fe(H 2 O) 5 (SCN)] 2+ could be calculated by using the limiting reactant’s, Fe(NO 3 ) 3 , initial concentration. Graph 1 Beer’s Plot for [Fe(H 2 O) 5 (SCN)] 2+ : In the graph, the slope, 7.9978E, is Beer’s constant. Graph 1 Beer’s Plot for [Fe(H 2 O) 5 (SCN)] 2+ , in the graph the standard curve was constructed using the concentration and absorbance values of Table 2. The purpose of creating this graph was to use the slope to determine the Beer’s constant, which was 7.9978E. The Beer’s constant can be used to calculate the unknown concentration of a solution with a known absorbance value using Equation 1. y = 7.9978E+03x R² = 9.9708E-01 0 0.05 0.1 0.15 0.2 0.25 0.3 0 0.000005 0.00001 0.000015 0.00002 0.000025 0.00003 0.000035 Absorbance Concentration (M) Absorbance vs. Concentration of [Fe(H 2 O) 5 (SCN)] 2+