This is a chemistry lab report on an Acid-Base Titration experiment.

2714 Words Apr 20th, 2002 11 Pages
Full Lab Report

Experiment #2:

Acid-Base Titration

Lab Description: Acid-Base Titration

Introduction

In this lab exercise we will evaluate the effectiveness of several indicators for the determination of the point of completion of a specific acid-base neutralization reaction. We will also determine the unknown concentration of the strong base NaOH by its reaction with a known amount of the weak acid, potassium acid phtalate (HKC8H4O4, abbreviated KHP). This will be accomplished using the titration method. The KHP solution will be created and its volume and concentration recorded. The KHP solution will be poured in a flask along with a few drops of one of three indicators we will be evaluating. The NaOH solution will be poured into a
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The solution was then swirled carefully in order to dissolve the solute. Since our beakers were large we were able to stir the solution contents with the magnetic stirrer without the fear of spilling any solution. This method was more effective and less time consuming than swirling the beaker. This solution was then poured into a 250ml Erlenmeyer's flask and a magnetic stir bar and several drops of phenolphthalein indicator were added. The flask was then placed on the magnetic stirrer with a white paper under the flask to allow for more contrast and facilitate the detection of a color change.

Once the experimental setup was complete, a 50ml buret was rinsed twice with 10ml of the NaOH solution from the plastic bottle. The buret was then filled with the NaOH solution and the initial NaOH volume mark was recorded. With the magnetic stirrer still on, we then placed the buret directly above the opening of the flask and slowly add NaOH to the acidic solution in the flask by slightly turning the stopcock. (It is essential that the magnetic stirrer be mixing the solution continuously so that there is no delay due to the time it take for the hydronium ions to collide with the hydroxide ions.) The instant the color of the solution changes permanently from clear to pink the stopcock must be closed and the final NaOH volume mark must be recorded. The resultant solution was then poured into the designated waste beaker, eventually to be discarded in the waste container.

The color
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