Chemistry post-Lab

Please wait... If this message is not eventually replaced by the proper contents of the document, your PDF viewer may not be able to display this type of document. You can upgrade to the latest version of Adobe Reader for Windows®, Mac, or Linux® by visiting http://www.adobe.com/go/reader_download. For more assistance with Adobe Reader visit http://www.adobe.com/go/acrreader. Windows is either a registered trademark or a trademark of Microsoft Corporation in the United States and/or other countries. Mac is a trademark of Apple Inc., registered in the United States and other countries. Linux is the registered trademark of Linus Torvalds in the U.S. and other countries.

Experiment 5 Report Sheet

Titrations: Accuracy and Precision

A.  Data Collection

Item

Trial 1

Trial 2

Trial 3

Trial 4

1.  Mass of KHP  Used (g) 

2. Initial Buret Reading (mL)

3.  Final Buret Reading (mL)

[4]  Volume NaOH solution Used (mL)

[5]  Moles KHP used (mol)

  [6]  Moles NaOH reacted with KHP (mol)

[7] Concentration NaOH sol. (mol/L)

[8] Average NaOH concentration (mol/L)

[9] Standard Deviation

In the following tables, items with [bracketed] numbers (i.e. [1]) are to be computed from your experimental data.  The others are collected as part of your experiment. 

1) If the buret had been wet with water and not adequately rinsed with base would your experimental value for concentration of NaOH be higher of lower than the true value? Explain

2) If you had performed all four titrations using the buret solution from question #1, would your error be systematic or random? Explain.

3) If 0.839 g of KHP were titrated, and 45.82 mL NaOH solution were necessary to reach the equivalence point, what is the concentration of the NaOH solution? (Make sure to report the correct number of significant figures).

4) The most common error when preforming a titration, is when additional titrant is added past the equivalence point.  If in your experiment you had added an excess volume of NaOH, the flask turned dark pink, how would this error affect your experimental value for concentration of NaOH? Concentration of NaOH would be higher, lower, or unchanged. Explain

B.  Post Lab Questions

8.0.1291.1.339988.308172