How to Carry Out Titration Experiment in the Lab

Titration is a quantitative approach to volumetric analysis, it is an experimental procedure in which a solution – called the titrant – whose concentration is accurately known from a graduated vessel(burette) is added to a known volume of a solution with unknown concentration – called the analyte until the chemical reaction between the two is just
completed.

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This is shown by a colour change in the resulting solution or in an added indicator.

In titration the molarity of one solution is usually known and this will aid in determining the molarity of the second solution. Therefore, in any titration, a standard solution must be used to react with a solution of unknown concentration.

Accurately measuring the amount or mole of titrant needed to neutralize the analyte, you can determine the concentration of the analyte very accurately.  The “end point” of a titration is the point at which the
titration is complete, it is the point after the equivalent point.

Typically when an added indicator solution such as phenolphthalein changes color. The “equivalence point” is closely related to but not necessarily identical with the end point.

The equivalence point is the point at which the number of moles of titrant exactly equals the number of moles (or
equivalents) of analyte. Ideally, the end point should exactly equal the equivalence point, but in the real world they are slightly different.

For example, you may titrate a hydrochloric acid analyte with a sodium hydroxide titrant, using phenolphthalein as an indicator. Phenolphthalein is colorless in acid solutions, and pink in base solutions, but no color change occurs until the pH of the solution reaches about 8.2, well into the basic range.

Note ; the concentration of a solution is the amount of solute in 1dm3 or 1000cm3 the solution. When titrating a weak acid against a weak base, there is no suitable indicator and as such any suitable indicator
can be used.

 In carrying out Acid base titration in the laboratory OR In simple terms, inroder for you to carry out titration experiment successfully in the Lab, the materials and precautions involved are as follows 

1. Weighing bottle 
2. Chemical balance 
3. Pipette 
4. Burette
5. Retort stand 
6. Clamp stand 
7. Funnel 
8. White tile
9. Conical flask 
10. Standard volumetric flask
11. Filter paper 

•  Precautions when using the Burette 

1. Rinse the inside of a clean burette thoroughly with the solution it will contain after you must have rinse it with distilled water and allow to dry.

2.Allow the solution to run out through the stopcock. Drain the burette completely. Repeat the rinsing at least once.

3. Make sure the outside of the burette is clean and dry, and then mount it securely to a laboratory clamp stand using a burette clamp of the proper size.

4. Fill the burette to the zero mark, using a graduated cylinder, small beaker, flask or other container. Use a funnel if necessary to prevent spillage.

5. Carefully run some solution through the stopcock to fill the burette tip completely, making sure there are no air bubbles and that the level of the solution falls to or below the zero. Meniscus mark.

6. Record the starting volume. When you complete the titration, you will subtract the starting volume from the final volume to determine the amount of solution you have added. (Read the volume from the bottom of the burette.

7. Remove the funnel after taking your reading.

8. Try to avoid inconsistent burette readings.

• Precautions when Using pipette

1. Carefully rinse the pipette with the solution to be contained (Base) after you might have rinsed it with distilled water

2.  Avoid air bubbles in the pipette

3. Make sure the mark to be read is at the level with your eyes

4. Do not blow the last drop on the pipette

•  Precaution When Using Conical Flask

1. Do not rinse it with any of the solution used in the titration process except distilled water.

2. Carefully wash down with distilled water any drop of the solution that sticks by the side of the conical flask during titration.

Furthermore, in a titration experiment on Quantitative and Qualitative Analysis:Acid -Base Titration , carefully follow the process below

1.Fill the burette with hydrochloric acid solution that has been standardized and adjust its level to the zero mark.

2. Pipette 2cm3 of the sodium hydroxide solution into the conical flask ( try to use pipette filler, but in case of absence, use your mouth to suck the base into the conical flask)  as seen on the diagram below

3.Add two drops of methyl orange indicator the colour should turn pink.

4. Carefully dispense the acid solution from the burette above into the alkali solution and swirl the flask after each addition to enable equal and proper mixture of the two solutions

5. Continue the process until the end point is reached, when the indicator turns orange.

6. Note the volume of the acid used to neutralize the alkali and record the final volume obtain.

7. The first titration is usually an approximate value, turn or discard your first titre value and carry out two more accurate titration

8. When approaching the end-point, add in the acid drop by drop until one drop of the acid changes the colour of the indicator permanently.

 Then record the burette readings. I hope this tutorial guide on how to carry out titration experiment help you in your titration endevour.

Now your turn

We would love to hear your thoughts,opinions and additional insights in relation to titration experiment. Carrying out titration experiment in the lab can be very easy and at the same time very difficult, it all depends on your level of preparation and focus.  so leave a comment below. OR Join Jaysciencetech Forum here to share your experience with other users/students.