Dr. S. Berniolles, Page 1 of 1 CHEM 6BL PRELAB/POSTLAB ANSWER KEY EXPERIMENT #2: VOLUMETRIC ANALYSIS OF AN ORGANIC ACID PRELAB ANSWER KEY: 1. (1 point) The criteria for a "primary standard" are: • Readily available in pure form • Easy to dry and not so hygroscopic (i.e., water attracting) that it takes up water during weighing process • Large molar mass to minimize the consequences of errors in weighing 2. (1 point) • Stoichiometric (equivalence) Point : point in a titration when just enough titrant has been added to react completely with the substance being titrated (i.e., analyte). • End Point : point in a titration when the indicator changes color. 3. (3 points) Dissolve 0.800 g of NaOH in (<200 mL) water , and then dilute it to exactly 200.00 mL (in a 200.00 mL volumetric flask). 4. (0 point) It is not critical to measure the volume of water in Step I.4 accurately because it is added to the NaOH solution to prepare a solution that will be standardized in Part II. 5.
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