Introduction: All chemical reactions must proceed until it has reached its equilibrium. Le Chatelier’s principle which can be described as when a system in chemical equilibrium is disturbed by a change in temperature, pressure, or a concentration, the system shifts in equilibrium composition in a way that tends to counteract this change in variable. Using this principle you will observe how certain substances react when the equilibrium has been distressed.
Objective: You will observe the application of Le Chatelier’s principle by observing the effects of acids and bases of on the solubility of Ca (OH) 2, the effects on Fe3+ and SCN- with Fe (SCN) 2+ to an equilibrium mixture. Also, finding the effects of an acid and base dealing with an indicator, and the effect on an acid on Ni2+, NH3, and Ni (NH3)62+.
Data and Data Analysis:
• Ca(OH)2 [pic] Ca2+ + 2 OH-
Data: You will first add 6 drops of Ca( NO3)2 to a watch glass. Then add 6 drops of HCl then add 6 drops of NaOH.
Analysis: Ca( NO3)2 ,a white milky solution, 6 drops of an acid such as HCl is added which turns colorless, and the Ca2+ becomes less soluble, which shifts the equilibrium to the right by removing the OH-. After adding the NaOH to the solution turns back to the milky solution that it once was, the Ca2+ becomes more soluble, which shifts the equilibrium to the left.
• Fe3+ + SCN- [pic] Fe(SCN)2+
Data: You will obtain 3 test tubes and label them 1, 2, and 3. Then add 20 mL of distilled water to the beaker. Next add 20 drops if Fe (NO3)3 and 20 drops of KSCN to the same beaker. Using the solution you just made pour 3 mL of the solution in each test tube. Add 20 drops of .1 M Fe (NO3)3 to test tube 1 shake gently. Add 20 drops of .1 M of KSCN to test tube 2 shake gently, and 20 drops of distilled water to test tube 3 shake gently.
Analysis: Test tube 1 after adding Fe (NO3)3 to...
Please join StudyMode to read the full document