Laboratory assignment for module 5: standardization of a solution

Name:

College ID:

Thomas Edison State College

General Chemistry II with Labs (CHE-122)

Section no.:

Semester and year:

 

 

LABORATORY REPORT

Laboratory Assignment for Module 5: Standardization of a Solution
(eScience Lab 7 [19])

 

 

 

I.       PURPOSE (10 POINTS)

 

 

 

 

 

 

II.    TEST DATA (15 POINTS)

Mass of beaker:

Mass of beaker and citric acid:

Mass of beaker and citric acid (after cooling):

Volume of NaOH:

 

Table 1. Trial 1 Data

Syringe Reading, mL

Citric acid added, mL

pH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 2. Trial 2 Data

Syringe Reading, mL

Citric acid added, mL

pH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

III. CALCULATIONS (15 POINTS)

 

Include your graphs with your report.

 

Mass of citric acid:

 

Moles of citric acid:

(MW = 192.0 g/mol)

 

Molarity of citric acid:

(volume of solution = 100 mL)

 

Trial 1 equivalence point:

 

Trial 2 equivalence point:

 

 

Show calculations

 

 

 

 

 

 

IV.  RESULTS (20 POINTS)

 

Molarity (Trial 1):

 

Molarity (Trial 2):

 

Average Molarity:

 

 

 

 

IV.  CONCLUSION (10 POINTS)

 

 

 

 

 

V.     QUESTIONS (30 POINTS)

 

1.      Use Figure 3 in your laboratory manual to determine which combination of acids and bases provide the most distinguishable equivalence point. Which combination is the most difficult to determine an equivalence point? (10 points)

 

 

 

2.      There are many different primary standards that could be used in a standardization titration. What are the criteria of a primary standard?(10 points)

 

 

 

3.      Potassium hydrogen phthalate (KHP; KHC8H4O4) is a good primary standard. If it took 20.0 mL of NaOH to react with 15.5 mL of 0.600 M KHP solution, what is the molarity of the NaOH solution? (10 points)

 

KHC8H4O4  +  NaOH    KNaC8H4O4  +  H2O

 

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