This document provides instructions for performing an acid-base titration experiment. The experiment involves titrating a solution of sodium hydroxide (NaOH) of known molarity with hydrochloric acid (HCl) of unknown molarity. Phenolphthalein indicator is used to detect the endpoint of the reaction, which is the point at which the moles of acid equal the moles of base. By measuring the volumes of the NaOH and HCl solutions before and after titration, the molarity of the HCl solution can be calculated using the titration equation. The document outlines the 12 steps of the experiment, which include gathering materials, adding solutions, titrating with stirring until the endpoint is

1. How to: Perform an
Acid-Base Titration
Connie Bisesi

2. Before Experiment:
Fill out the know and want to know sections of
the following KWL chart regarding acid-base
titrations:
file:///Users/uconn922/Desktop/KWL%20Sheet
%20For%20Connie%20Bisesi.webarchive

3. What is an Acid-Base Titration?
An acid or base of known concentration
neutralizes an acid or base of the unknown
centration.
The experiment is monitored by visual
indicators and pH electrodes in order to find the
reaction’s equivalence point.

4. Purpose of the Experiment
In this acid-base titration, you will determine the
molarity of an unknown solution of NaOH
(base) by titrating in with a known solution of
HCL (acid). To do so, use the equation:
M1 x V1 = M2 x V2

5. Key Things to Note
In order to know when neutralization has
occurred, a sudden color change in the
indicator will be present. This means that the
moles of the acid is equal to the moles of the
base, called the endpoint.

6. Brief Overview of Experiment
https://www.youtube.com/watch?v=g8jdCWC10vQ

7. Step 1: Hypothesis
Form a hypothesis (an educated guess) about
the results of the experiment. You will be
testing the accuracy of your hypothesis.

8. Step 2: Gather Materials
● 50 mL Buret
● 10 mL Graduated
Cylinder
● Distilled Water
● Phenolphthalein
● Buret Clamp
● Safety Goggles
● 125 mL Erlenmeyer Flask
● 200 mL beaker
● .1 M NaOH
● HCl
● Stirring plate

9. Step 3: Clean Equipment
Rinse the buret, graduated
cylinder, and erlenmeyer
flask with distilled water.
Dry the equipment
thoroughly with paper
towels.

10. Step 4: Addition of NaOH
Set up the buret to sit nicely in the buret clamp,
with a 200 mL beaker beneath it. Add 50 mL of
base (NaOH) to the buret. Make sure to get rid
of air bubbles in the lower end by opening the
spout on the bottom. Record the volume to the
nearest .01 mL in the data table.

11. Data Table
Amount of Solution (in mL)
Initial volume of .10 M NaOH (in buret)
Initial volume of HCL (in beaker)
Final volume of .10M NaOH (in buret)

12. Step 5: Obtaining HCl
Obtain 10 mL of HCl by measuring it out in the
graduated cylinder, and transferring it to the
erlenmeyer flask.

13. Step 6: Addition of H2O
In the erlenmeyer flask, add 50 mL of distilled
water (measured with the graduated cylinder)
and two drops of phenolphthalein. Record the
volume in the data table.

14. Data Table
Amount of Solution (in mL)
Initial volume of .10 M NaOH (in buret)
Initial volume of HCL (in beaker)
Final volume of .10M NaOH (in buret)

15. Step 7: Magnetic Stirrer
Place the erlenmeyer flask on the stirring plate
under the tip of the buret (removing the beaker)
on a moderate speed, 5.

16. Step 8: Titration
Very slowly, add 1 mL from the buret into the
erlenmeyer flask until the solution in the flask
turns a faint pink for more than 30 seconds.
Note: If the color in the flask turns to a dark
pink, the solution was over titrated.

17. Step 9: Measuring End Point
Measure and record the volume of the buret at
the end point of the reaction in the data table.

18. Data Table
Amount of Solution (in mL)
Initial volume of .10 M NaOH (in buret)
Initial volume of HCL (in beaker)
Final volume of .10M NaOH (in buret)

19. Step 10: Cleaning of Equipment
Turn off the stirring plate and release the buret
from the buret clamp. Wash all the equipment
with distilled water, dry, and put away in its
correct place.

20. Step 11: Calculate Molarity
Plug in your data and solve for M2 ( the
concentration of HCl)
M1 x V1 = M2 x V2
M1: .10 M
V1: Final volume - initial volume of NaOH
V2: Initial volume of HCl

21. Step 12: Review Hypothesis
Review whether your results match your
hypothesis and either accept or reject it. Lastly,
finish the what I have learned in the following
KWL chart:
file:///Users/uconn922/Desktop/KWL%20Sheet
%20For%20Connie%20Bisesi.webarchive