Last modified: Mon 10/14/2013 05:50:09 pm
BCE

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Answer all of the questions below. If you do not know an answer enter CNA. However, it will help me the most if you answer each question with your best intuition/idea about what would be a reasonable answer.

First Name:

Last Name:

Laboratory Section:

In this BCE you will measure the pH of several aqueous solutions of acids and bases. You will use a pH meter simulation developed at Iowa State University by Dr. Greenbowe. Open the simulation (it will appear in a new window), and resize the window so it is easy to move between the simlation window and the BCE. Adjust the "solutions" settings to "acid" (or "base"). If this is the first time using the simulation click on HCl (in the left column of acids) and then set the concentration (in the boxed Molarity section below the pH meter) to 10 x 10-2 M and the volume setting to 100 mLs.

1a. Complete the pH column in the following table by systematically selecting an acid or base from the left column list of acids and bases (you will have to click on the "bases" button to view the list of bases), adjusting the concentration of the solution to 10 x 10-2 M (or 0.100 M) and the volume of the solution to 100 mL, and then clicking on the Insert Probe (lowers the pH probe into the solution and provides a digital readout of the solutions pH) button on the pH meter.

 

Solution

pH

Equilibrium [H+] or [OH-]

0.100 M HCl

[H+] =

0.100 M HNO3

[H+] =

0.100 M H2SO4

[H+] =

0.100 M HC2H3O2

[H+] =

0.100 M NaOH

[OH-] =

0.100 M NH3

[OH-] =

b) Complete the Equilibrium [H+] or [OH-] column by using the pH to calculate the [H+] or [OH-] for each acid or base. To calculate the [H+] or [OH-] given the pH of a solution review the information on page 726 -729 in your textbook.

2a. Each of the acids in the table above has the same concentration, 0.100 M. Did all of the acids have the same pH? (Yes or No)

b) What do you think might be an explanation for the experimental pHs you observed for this set of acids.

3a. Each of the bases in the table above has the same concentration, 0.100 M. Did all of the bases have the same pH? (Yes or No)

b) What do you think might be an explanation for the experimental pHs you observed for this set of bases.

4. Is there anything about the questions that you feel you do not understand? List your concerns/questions.

5. If there is one question you would like to have answered in lecture, what would that question be?