Titration Laboratory

2081 Words Apr 21st, 2013 9 Pages
Colegio Católico Notre Dame
Caguas, P.R

Laboratory:
Titration of an Acid with a Base

Tristian Pérez Rivera
12-136
AP Chemistry
Professor Judith Martínez PhD

Objective * The purpose of this laboratory is to recreate and understand what titration is.
Hypothesis
* If the experiment works correctly, we should determine the amount of a substance by adding a carefully measured volume of a solution with known concentration until the reaction of both is complete.
Materials
* Computer
Pre-lab
1. How will you know when your titration is finished? I will know that the titration is finished when the color of the indicator changes, meaning that the equivalence point has been reached.
2. Draw and label the pH scale below with acid, base,
…show more content…
Phenolphthalein changes from white to pink at a pH of 8.2-10.0. Bromothymol blue changes from yellow to blue at a pH of 6.0-7.6. In my case, I used Bromothymol blue for all because the equivalence point for a strong acid being titrated by a strong base is at a point near the neutral position.

6. (a) Why is it important for the buret to be clean before using? How do you clean a buret?
It is important to clean the buret thoroughly before using it because it will help for the buret to perform better and will minimize or even prevent error in the experiment.
(b) Why are air bubbles in the buret tip a possible source of error in a titration experiment? How do you remove air bubbles from the buret tip? Air bubbles in the buret tip can cause error in a titration experiment because it can cause the reader to read an inaccurate value of the volume in the buret. One can remove air bubbles by draining several milliliters of the titrant into a waste beaker.

7. Predict the products of these reactions.
(a) HNO3 (aq) +KOH (aq) KNO3 (aq) + H2O (l)
(b) HCl (aq) + Ca (OH) 2(aq) CaCl2 (aq) + 2H2O (l)
(c) NH3 (aq) + H2SO4 (aq) HSO4- (aq) + NH4+ (aq)
8. For the reactions (a) and (b) in question 8, how many moles of the base are required to neutralize one mole of the acid? How many mL of 0.100 M base are required to neutralize 10.00 mL of 0.100 M acid?
(a) It takes 10.0mL of the 0.100M base to neutralize the 10.0mL of the 0.100M acid

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