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The Titration Process Titration is the process to determine the concentration of chemical compounds using a standard solution. Titration involves dissolving a sample using a highly purified chemical reagent, called a primary standard. The titration technique involves the use of an indicator that will change color at the endpoint to indicate that the reaction is complete. The majority of titrations are carried out in an aqueous solution, however glacial acetic acids and ethanol (in petrochemistry) are occasionally used. Titration Procedure The titration procedure is a well-documented, established quantitative chemical analysis technique. It is utilized in a variety of industries, including pharmaceuticals and food production. Titrations can be performed manually or by automated devices. Titration involves adding a standard concentration solution to an unidentified substance until it reaches the endpoint or equivalent. Titrations can be carried out using various indicators, the most commonly being phenolphthalein and methyl orange. These indicators are used to signal the end of a test, and also to indicate that the base has been neutralized completely. You can also determine the point at which you are by using a precise instrument such as a calorimeter, or pH meter. Acid-base titrations are the most frequently used type of titrations. These are usually performed to determine the strength of an acid or to determine the concentration of the weak base. In order to do this the weak base is converted to its salt and titrated against the strength of an acid (like CH3COOH) or a very strong base (CH3COONa). The endpoint is usually identified by a symbol such as methyl red or methyl orange which turns orange in acidic solutions, and yellow in neutral or basic ones. Another type of titration that is very popular is an isometric titration that is generally used to measure the amount of heat produced or consumed during an reaction. Isometric measurements can also be performed with an isothermal calorimeter, or a pH titrator that analyzes the temperature changes of a solution. There are a variety of factors that could cause failure in titration, such as improper handling or storage, incorrect weighing and inhomogeneity. A large amount of titrant may also be added to the test sample. The best way to reduce the chance of errors is to use an amalgamation of user training, SOP adherence, and advanced measures to ensure data integrity and traceability. This will minimize the chances of errors occurring in workflows, particularly those caused by handling samples and titrations. It is because titrations may be done on very small amounts of liquid, which makes these errors more obvious than they would with larger batches. Titrant The titrant is a solution with a specific concentration, which is added to the sample substance to be measured. This solution has a characteristic that allows it to interact with the analyte through a controlled chemical reaction which results in neutralization of acid or base. The endpoint is determined by watching the change in color, or by using potentiometers to measure voltage using an electrode. The amount of titrant dispersed is then used to calculate the concentration of the analyte in the initial sample. Titration can be done in a variety of different methods, but the most common way is to dissolve both the titrant (or analyte) and the analyte into water. Other solvents such as glacial acetic acids or ethanol can also be used to achieve specific objectives (e.g. Petrochemistry, which is specialized in petroleum). The samples must be in liquid form to perform the titration. There are four kinds of titrations: acid-base diprotic acid titrations as well as complexometric titrations, and redox titrations. In acid-base tests, a weak polyprotic is being titrated using the help of a strong base. The equivalence is determined using an indicator such as litmus or phenolphthalein. In laboratories, these types of titrations can be used to determine the concentrations of chemicals in raw materials like oils and petroleum-based products. Titration is also used in the manufacturing industry to calibrate equipment and monitor quality of finished products. In the industries of food processing and pharmaceuticals Titration is a method to determine the acidity and sweetness of food products, as well as the amount of moisture in drugs to make sure they have the right shelf life. Titration can be done by hand or using the help of a specially designed instrument known as a titrator, which automates the entire process. The titrator will automatically dispensing the titrant, monitor the titration reaction for visible signal, identify when the reaction has complete, and calculate and save the results. It can even detect when the reaction isn't complete and prevent titration from continuing. The advantage of using a titrator is that it requires less training and experience to operate than manual methods. Indicator An indicator is a chemical that undergoes a distinct, visible change when the conditions of its solution are changed. This change is often a color change but it could also be bubble formation, precipitate formation or temperature changes. Chemical indicators can be used to monitor and control chemical reactions such as titrations. They are often found in chemistry labs and are useful for demonstrations in science and classroom experiments. The acid-base indicator is an extremely common kind of indicator that is used for titrations and other laboratory applications. It is comprised of the base, which is weak, and the acid. The indicator is sensitive to changes in pH. Both the acid and base are different shades. Litmus is a reliable indicator. It changes color in the presence of acid and blue in the presence of bases. Other types of indicator include phenolphthalein, and bromothymol. These indicators are used to track the reaction between an acid and a base, and can be helpful in finding the exact equilibrium point of the titration. Indicators are made up of a molecular form (HIn) and an Ionic form (HiN). The chemical equilibrium that is created between the two forms is pH sensitive and therefore adding hydrogen ions pushes equilibrium back towards the molecular form (to the left side of the equation) and creates the indicator's characteristic color. The equilibrium is shifted to the right away from the molecular base and towards the conjugate acid when adding base. This results in the characteristic color of the indicator.
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