ApchemWiki | RecentChanges | Preferences
This lab will consists of two parts as follows:
a) Each group will make one of the solutions below and place around 20.ml into a 100.ml beaker and label it with Molarity and solution's chemical formula.
b) Each group will determine the pH with a) pH paper (record pH to the tenth place) and b) LabQuest2 pH probe of each of the 4 solutions.
c) Each group will also determine the color change on the red and blue litmus paper.
c) Each group will then calculate (in their lab book) the theoretical pH of each solution. Show all work as if calculations are part of a test.
The solutions to be made are (any leftover solution will be put into plastic containers with label of molarity and chemical formula):
a) 1.0M HCl solution, 500ml of this solution (from a concentrated, (concen), 12.0M solution)
b) 1.0M HC2H3O2 solution, 500.ml of this solution (from a concen 12.0M solution)
c) 1.0M NaOH solution, 500.ml of this solution (from a solid NaOH).
d) 1.0M NH4OH solution (it is called ammonium hydroxide but the other name is ammonia water solution), 500..ml of this solution (from concen 14.5M solution)
e) 2.0M HCl solution, 500mL of this solution from concen 12.0M solution
Please show your calculations on making "your" solution. Show all work as if it was a problem on a test. Share with other groups so everybody have the calculations needed to make the 4 solutions (these calculations will be part of your lab write-up.)
2017-2018 AP Chem Extension
a) To the 1.0 M HCl solution, add a few grains of NaCl, stir/dissolve salt and record new pH.
b) To the 1.0M HC2H3O2 solution, add a few grains of Sodium acetate ( NaC2H3O2), stir/dissolve and record new pH.
c) To the 1.0M NaOH solution, add a few grains of NaCl, stir/dissolve salt and record new pH.
d) To the 1.0M NH4OH solution, add a few grains of Ammonium chloride ( NH4Cl ), stir/dissolve and record pH.
Question for 2018-2018 AP Chem Extension. (Will answer these questions on different sheet of paper)
1. What would LeChatlier's Principle about adding NaC2H3O2) to a HC2H3O2 solution? What would the new Equilibrium "bucket" look like and do any concentrations change? Do those changes the pH of the new solution compared to the original solution?
2. Similarly, how would the same thing happen when you added NH4Cl to the NH3 ( i.e. NH4OH solution).
3. Does the same thing happen when added the NaCl to either the HCl solution and/or NaOH solution? Explain?