Titration experiment essay PDF

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Summary

Titration lab report
Quantitative analysis
Procedure
Human errors...

Description

The Quantitative Analysis experiment performed was to Standardize the Iodine Solution. In this analysis, there are many sources of errors which may occur as well as ensuring that accuracy, precision and its reliability is controlled in the procedure. Titration is recognized as a highly sensitive analytical method which could easily determine the unknown concentration of a chemical within the solution by introducing a known concentration from another chemical. The solution of the known concentration is introduced within a specific volume of the unknown from a Burette. These indicators determine when a reaction has come to an end. The first step is by taking an 100ml Volumetric Flask and placing it on the workbench as well as taking the Erlenmeyer Flask. The problems encountered when handling glassware is that it may break due to not placing the glassware on the surface of the table but placing it on the edge of the table. Another problem encountered is that students may tend on not handling the equipment appropriately. For instance, when handling a flask the students may handle it from the neck of the flask as this may result in any risks or accidents. In order to avoid this error, prevent handling the glassware in the wrong way as well as making sure that all glassware is placed safely and in the right area. The next step is to be able to add 0.100g of Ascorbic Acid into the Volumetric Flask and 30 ml of water to allow the Ascorbic Acid to dissolve and filling in the flask with the water until it reaches a 100 ml mark. The problems encountered in this step is when applying the Ascorbic Acid within the volumetric flask. This Vitamin C type has a chemical danger that the substance is a strong reducing agent which reacts with oxidants and the solution in water does have a medium strong acid. Due to the fact that the Ascorbic Acid has an effect on the skin and eyes as it is irritant and also have an affect on the Respiratory Tract, you must avoid and control these risks by not letting the substance touch the skin or anywhere on the body which is by wearing protective clothing of a Laboratory Coat, Safety Goggles as well as gloves. Also, to make it easier, students could use a pipette or a measuring cylinder to transfer the acid and to avoid any spillage. And to give a precise and a reliable measurement, a measuring cylinder is useful to use and apply it into the flask. To perform the coarse titration, you first take a Burette and place it on the workbench adding 50.00 ml of Iodine Solution which is later recorded as an initial Burette reading. The problems encountered when pouring the Iodine Solution into the Burette is overshooting it over the line. This would result inaccuracy and not a precise measurement as pouring more than enough of the Iodine Solution would mean that you would have to repeat the titration all over again. In order to avoid this you must position yourself so that use a plastic pipette to be able to apply the

rest of the solution in drops once you are close to the end point to avoid repeating the procedure all over again. Overshooting the meniscus would result in a lower molarity. Cross contamination is very essential during an experiment and that is one major error. A possible error in the Redox Titration is using any contaminated equipment and not rinsing with distilled water it before reusing it when repeating the experiment. Having two different solutions could cause serious risks depending on the solid or chemical. This means to avoid any of these issues and to make sure the experiment stays as accurate as possible, the equipment must be rinsed out with distilled water. Also, using unwashed equipment is crucial especially performing the Titration as it can ruin your calculations. For example, if a glass beaker was not properly sterilized, it can contaminate with old reagents which can also change the concentration of the solution. To link it with calculations, the measurements will not be exact. Rinsing the Burette with water and performing a Titration can be a possible error. This is because there may be residual water in the Burette which would give off a unreliable and inaccurate result. This indicates that in order to avoid this error, students must ensure that no drops of water is in the Burette and that it must be carefully dried out before beginning the procedure. This can also be a human error due to the case that students may tend to rinse out the equipment and materials after the solution is transferred. This indicates that a replacement of the equipment should be present if needed to rinse a piece of equipment or material as a small substance of the fluid can easily affect the Titration results. This suggests that replacing the materials is a good source to ensure accuracy and reliable results. When adding the Ascorbic Acid and water into the Volumetric Flask, a possible error is that students may not have swirled in both the substances together. This may lead with an inaccurate result as when applying the iodine solution in the flask and including the some of the Ascorbic Acid also, is not carefully swirled which could cause inaccuracy. This suggests that in order to avoid this error, students must ensure that all contents are carefully swirled together to give off an indicator in the Flask. This also ensures that there are no contents sinking at the bottom of the solution. Misreading a Volume can be a possible error encountered in terms of performing the Redox Titration. The accuracy of Titration can depend on the accuracy of the known concentration change. The error is that the Burette can be misread by students by looking at the measurement of the angle. Once you look above the volume, it looks lower than the actual measurement as well as if you look below at the measurement, the volume of the solution would look less of the

solution amount. Another error when misreading the Burette is that the solution is able to form a concave curve which is at the bottom as the bottom of the curve is present to be able to easily measure the volume. However, once the reading is taken from a higher section from the curve, it is an error. This is the indication that in order to prevent this error as well as ensure that students gain accurate results when reading the volume, the solution should be in line with the meniscus and measured carefully to give off reliable and valid results. Nonetheless, a Human error which may be encountered performing Redox Titration is that students may misread the procedure when performing the practical. For instance, things such as pouring too much or too little of the materials within the Flask or Burette as this may result in the Titrant not giving off an indicator as the iodine solution is involved. Also not following the method is an error as it can be a health and safety issue. This indicates that in order to avoid this error, you must ensure that a technician or a member of staff is present to be able to guide them with any dangers.

References: http://sciencing.com/errors-titration-experiments-8557973.html https://answers.yahoo.com/question/index?qid=20130615161006AAoRNC8 https://www.thestudentroom.co.uk/showthread.php?t=384726...