A&E due 2-10

.pdf

School

Purdue University *

*We aren’t endorsed by this school

Course

112

Subject

Chemistry

Date

Jan 9, 2024

Type

pdf

Pages

2

Uploaded by MinisterSeaLion2546

Report
Activities and Explorations: 10 points, Due Sunday Feb. 26, 11:59 PM Claim, Evidence, Reasoning: Buffers Instructions: Upload your work on this page to Brightspace by typing or writing your responses and saving the file and uploading that file as a docx or pdf (not HEIC or pages). You can also take pictures of your written work and paste them into this document and save is as a docx or pdf. Learning Objectives 16.3 Buffer Solutions Define a buffer. Predict the relative pH change for a given buffer system after addition of strong acid or strong base. Instructions: Work through the experiment below and determine which of the solution(s) might be a buffer based upon the experimental data. Imagine you have 50 mL of each of three solutions labeled A, B, C and you go about carrying out the following experiments to determine which of the solutions possibly are buffers. The experimental set up for the test tubes is shown in Table 1 below and the data gathered is in Table 2. Table 1: Experimental Set Up. Experimental procedure Part I Experimental procedure Part II 1. Remove 5 mL of each solution and place it in a test tube and measure the pH. Data is recorded in Table 2 below. 3. Obtain 3 new clean test tubes. Remove 5 mL of each solution and place it in a test tube. 2. Add a small amount, 4-5 drops, of 0.001 M HCl to each test tube and measure the pH. The results are shown in the Table 2. 4. Add a small amount, 4-5 drops, of 0.001 M NaOH to each test tube and measure the pH. The results are shown in the Table 2. Table 2: Experimental Data for each Solution (A, B, and C). Solution A B C Measured pH of 5 mL sample (step 1) 3.56 9.98 7.00 pH after addition of HCl (step 2) 3.48 9.90 1.63 pH after addition of NaOH (step 4) 3.64 10.08 12.30 A C B
1. Which solution or solutions are buffers (this is your claim)? A and B are the buffers due to the fact that they barely changed. 2. Justify and explain your answer to #1 using the data in the table above and the definition of a buffer. (You must include the definition of a buffer in your response!) Buffers can be defined as solutions that don’t change when acids or bases are added. Based upon the chart you can see that solution A and B stayed mostly consistent while exposed to both HCl which is an acid and NaOH which is a base. Compared to solution C which has a drastic change when exposed to the acids and bases.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help