Site Loader

How Does a Buffer Affect pH?Overview/Objective The buffer solution that we are creating is ultimately a combination of an acid that is weak and its specific conjugate base.  When a strong acid is added to a buffer solution, the conjugate base associates with the H positive ions of the strong acid. This preserves the pH of the solution. Likewise, if a strong base is added, the weak acid will associate with OH ions. Buffers are most effective when the concentrations of the acid and base are equal. The resistance to pH change of this buffer will be compared to a HCl solution and distilled water by adding strong acids and bases and measuring the pH with pH paper.Our first objective within this experiment was to create a buffer. The buffer included equal amounts of acetic acid and sodium acetate. The ultimate goal within this experiment is to measure the pH changes in solutions when an acid or base is added to them. Then we would ultimately compare these pH changes in a strong acid, distilled water, and a buffer solution.Materials:2, 12 well reaction platesTransfer pipettes4.8 pH HCl solution0.5 M acetic acid0.5 M sodium acetatepH paper0.1 M HCl0.1 M NaOH10 mL graduated cylinder Goggles (safety)Procedure: First thing you need to create your buffer and to create your buffer you need to combine 5 mL of 0.5 M acetic acid with 0.5 M sodium acetate. Add 15 drops of pH 4.8 HCl solution to nine wells of your 24-well reaction plate.Test the pH of one of these wells with pH paper.  Record in data table.Add 15 drops of 4.8 buffer solution to nine different wells of your 24-well.Test the pH of one of these wells with pH paper.  Record in data table.In a second 24-well plate, add 15 drops of distilled water into 9 wells.Test the pH of one of these wells with pH paper.  Record in data table.Add 15 drops of distilled water to 3 wells of 4.8 pH HCl, 4.8 pH buffer, and distilled water.Use pH paper to record the pH of one of these wells for each type of solution.  Add 3 drops of 0.1 M HCl to 3 wells of HCl solution, buffer solution, and distilled water.Use pH paper to record the pH of one of these wells for each type of solution.Add 3 drops of 0.1 M NaOH to 3 wells of HCl solution, buffer solution, and distilled water.Use pH paper to record the pH of one of these wells for each type of solution.Data: SolutionInitial pHpH after 15 drops H2OpH after 3 drops 0.1 M HClpH after 3 drops 0.1 M NaOHHClpH 2pH 2pH 1pH 2BufferpH 6pH 6pH 7pH 7H20pH 7pH 7pH 2pH 12

Post Author: admin

x

Hi!
I'm Erica!

Would you like to get a custom essay? How about receiving a customized one?

Check it out