Titration Is A Measured Volume Of Acid

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A titration is used to determine the amount of acid in a given solution. This is done by titrating a measured volume of acid (in this instance, acetic acid (CH3COOH)) with a solution of a strong base (usually sodium hydroxide (NaOH)), of a known concentration. The NaOH is added in small aliquots until the acid has been neutralised, and this can be determined with an indicator dye, such as phenolphthalein, or a pH meter (Nelson & Cox, 2008 pg58). In this practical, a pH meter was used and this allows for the acidity or alkalinity of a solution to be measured, and this was more accurate than using an indicator dye. The use of the pH meter in titration is generally preferred more over the visual indicator because the equivalence point can be measured more accurately than relying on the change of colour, which can often result in overshooting. Therefore, by using the pH meter the chance of indicator blank error is eliminated. Titration is a technique which is often used in the medical and chemical industry because it is a relatively simple process that can be used in various forms to develop or analyse chemical compounds (Highland,J. 2011). The purpose of titrating CH3COOH with NaOH was to detail the changes in pH that occurred during the titration. By producing a pH titration curve it allows for an understanding of how the relationship between the pH, the pKa and the ratio of the acid and conjugate acid-base concentrations work within a buffer. A buffer is a solution that can resist pH change upon the addition of acidic or basic components. The conjugate acid-base system (which is a mixture of the CH3COOH and acetate ions) can donate and receive protons, and therefore by doing this they can resist pH changes. This buffering capabilit... ... middle of paper ... ...ch could have affected the data collected. For example, the pipetting of the NaOH into the CH3COOH, this could have been an error because if the amount of solution pipetted wasn’t 0.5ml than the speed of the titration could have varied and this could have given incorrect data. Most of the equipment used in a laboratory environment has a degree of uncertainty. The pH meter has a degree of uncertainty that is +0.001 pH, which means that the pH measurements that are determine by the pH meter can be as much as one-hundredth of a pH off from the true measurement (Perles,C. 2013) Improvements could have been made to limit the chance of error occurring, such as ensuring the correct amount of solution is being pipetted, and this can be done by asking a supervisor for assistance. However, some limitations cannot be prevented, such as the degree of uncertainty of the pH meter.
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