Lab_7_Part_I_and_II.docx - Experiment#7 Equilibrium Part I...

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Experiment #7 Equilibrium Part I By Francisco Guayaquil CHEM 114.1 General Chem. II Lab 03.24.2020
ABSTRACT In this experiment, we study equilibriums in two ways: by manipulating a spreadsheet stimulation and observing the effects in an actual chemical reaction. By observing and completing the experiments, we learned that the NaOH causes the reaction C 27 H 28 Br 2 O 2 S (yellow) + OH - C 27 H 27 Br 2 O 2 S (blue) + H 2 O to shift right and HCl causes it to shift left and turn yellow. Also, adding more Fe 3+ and SCN - to the reaction Fe 3+ + SCN - FeSCN 2+ causes the reaction to shift right. THEORY Equilibrium occurs when the forward and reverse reaction rates are the same. However, if there is a stress that causes equilibrium to be lost, the two reactions will no longer be equal. This will cause a change in the state of the reaction because the system will eventually have to return- back to equilibrium using the inequality rates. The system will shift to regain its balance. This happens, for example, if some stress causes the rate of the forward reaction to become faster than that of the reverse reaction. This would cause the number of reactants to decrease and the products to increase. There would be a conversion of reactants to products. This is known as a shift to the right. This can occur vice versa with a shift to the left, where the products decrease, and the reactants increase. 1
PROCEDURE & DATA This section of the experiment had three parts. In the first part of the experiment, we started by pouring 25 mL of tap water into a 125 mL flask and then adding a few drops of Bromothymol blue solution. Next, about 2 drops of dilute NaOH solution was added, mixed in and the color was recorded. Then, we added a couple of drops of dilute HCl solution, swirled, and recorded the color. In the second part of the experiment, we mixed 25 mL of FeNH 4 (SO 4 ) 2 solution and 25 mL of NaSCN solution and divided it up into five test tubes. We 2.0 mL of 0.5 M FeNH 4 (SO 4 ) 2 was added to the second test tube. In the third test tube, 2.0 mL of 0.5 M NaSCN solution was added. In the fourth, about 5 drops of 5% AgNO 3 solution was added. The last test tube received approximately 10 drops of EDTA 4- solution. The color change and the shifts for each was recorded. For the final part of the experiment was, in a 50 mL beaker, 10 mL of 0.4 M Co(NO 3 ) 2 and 6 mL of 12 M HCl were mixed together. The mixture was divided into three test tubes. One test tube was placed in ice while the another was placed into a hot water bath. We recorded the colors of both. 2
CONCLUSSIONS AND QUESTIONS The three components in section two of the experiment, we study equilibrium and the effect of removing or adding species

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