CHEM120L Study Guide - Sodium Hydroxide, Molar Mass, Stopcock
9 Dec 2014
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Document Summary
Acid-base titrations: the identification of an unknown solid. In part a the procedure was the standardization of sodium hydroxide (strong base) using oxalic acid (weak acid). When titrating with a strong base and weak acid we are essentially transferring protons from the weak acid to the hydroxide ion. The balanced equation of the standardization can be shown by h2c204 + 2oh- 2h20 + c2o4. 2- the oxalic acid is diprotic containing two h+ ions per mole and will react with two moles of hydroxide ions. This can cause a source of error because the acid can potentially neutralize the base with a single drop and if the stopcock is relatively high the end point can be surpassed. As well in terms of the burette the values were +- . 5ml, which can result in a source of error. The primary standard is 100% pure, so the titration should give perfect accuracy for the entire analysis (lab manual).
