Please write the procedure in your own wordsPlease write it in a paragraph Please please please answer as fast as possible please NOTE: Both images go together PART A - PREPARATION1. Obtain an unknown sample from your instructor. If the sample is not labeled with thequantity of sample to use for each run, ask your instructor for the information. Keep theunknown tightly stoppered to avoid absorption of moisture from the air. Record theunknown number and the concentration of the standard NaOH (to 4 significant figures).Weigh the sample on a weighing boat to ±0.0001 g, and transfer the solid directly to a250 mL beaker. Add approximately 20 mL of water, mixing it well until it is dissolved. Ifit does not dissolve, heat the mixture gently on a hotplate (NOT with a Bunsen burner!).After the sample has dissolved, let it cool slightly and add enough water to bring thevolume up to approximately 100 mL.NOTE: In this experiment, the amount of the weak acid is determined through weighing.The volume of water does not appear in the calculation and therefore it is not important tomeasure it precisely.2. You will need approximately 50 mL of standardized NaOH solution for each titration.The concentration should be about 0.1 M. Clean, condition, and fill a buret with thestandard NaOH solution. Your initial reading should be 0.00 mL.3. Connect a pH sensor to Channel 1 of the Vernier handheld unit. Connect the handheldunit to the computer using the USB cable. Calibrate the pH sensor as you did in theprevious experiment, using the 4.0 and 7.0 buffers.PART B - TITRATION1. Place the beaker with the unknown sample on a stirring plate and put in a stirring bar.Rinse and dry the sensor with a Kimwipe, and insert it into the unknown weak acidsolution so that the tip is at least 0.5 inch to 1 inch below the surface and away from themagnetic stirring bar. (The glass bulb must be covered by solution.) The stirrer should beturned off before any pH readings are taken.electrodeFigure 2. Thetitration set-up.Stirring barMagnetic stirrer2. Run the Logger Pro program on your computer. Open the file "07a Acid-Base" from theAdvanced Chemistry with Vernier folder.3. You are now ready to begin the titration.a. Before adding any NaOH titrant, click Collect. Once the displayed pH reading hasstabilized, click > Keep. In the edit box, type 0.00 (for 0 mL base added). Press theENTER key to store the first data pair for this experiment.b. Add the next increment of NaOH (enough to raise the pH by about 0.15 units). Whenthe pH stabilizes, again click Keep. In the edit box, type the buret reading and pressENTER. This is the second data pair for the experiment. C.Continue adding NaOH in increments that raise the pH by about 0.15 units and enterthe buret reading after each increment. When a pH reading of 4-4.5 is reached, switchto smaller increments. You will want to be adding one or two drops at a time as youapproach the equivalence point.d. After a pH reading of approximately 10 is reached, add larger increments that raisethe pH by about 0.15 pH units and enter the buret reading after each increment. Youmay stop adding base and taking readings about four milliliters after the titrationcurve begins to level off.4. When you have finished collecting data, click STOP. Dispose of the reaction mixtureas directed. Rinse the pH sensor with deionized water in preparation for the secondtitration.5. Follow the steps below to find the equivalence point, which will be where there is thelargest increase in pH upon the addition of a very small amount of NaOH solution. Agood method of determining the precise equivalence point of the titration is to take thesecond derivative of the pH-volume data, a plot of A²pH/Avol².a. View a plot of the second derivative on Page 3 by clicking on the Next Page button.b. Analyze the second-derivative plot and determine the volume of NaOH at theequivalence point. The equivalence point is the x-intercept; the second derivative (f")will go from a high positive value to a big negative value. Use the range markers andthe linear regression function to get an equation for the line connecting the high andlow f' values, and then solve for x. That will be Vep.6. The buffer-point volume (Vbp) will be one-half the equivalence-point volume. Using thetitration-curve graph, put the range markers around Vы and a couple data points on eachside. (This part of the graph should be essentially linear.) Use the range markers and thelinear regression function to get an equation for the line, and then solve for y. This will bethe pH at the buffer point; it is also the pKa.7. Print your graphs and the appropriate data. For the pH titration graph, the data showingshould be in the buffer region. For the second-derivative graph, the data showing shouldbe around the equivalence point. If you wish to save your results, choose Store LatestRun from the Experiment menu.8. Perform a second titration. If your added increments were too large in your first run,make the necessary modifications to your procedure.9. Perform a third titration if necessary.

The objective of this question is to evaluate the laboratory procedure for determining the…

Answered: Please write the procedure in your own…

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...