A titration is a form of quantitative chemical analysis commonly used to ascertain the concentration of a known solution by reacting it with a solution of a known concentration. 2 of the most common forms include: acid-base and redox. Acid-base titrations involve acidic and alkaline solutions that will react with each other; scientists can use strong or weak bases vs strong or weak acids. Redox titrations involve reacting solutions with reducing or oxidising agents and adding indicators to detect endpoints of the reactions. 1 In an acid-base titration, an acidic or basic titrant (determined by pH, where less than 7 is acidic, greater than 7 is base/alkaline) is reacted with an analyte that is either a base or an acid. 2 Then, as the titrant’s concentration is known, as well as the volume of it added to the analyte and the reaction’s stoichiometry, the analyte’s concentration can be calculated. The point at which enough titrant has been put in the analyte solution to react with it completely is known as the equivalence point. 3 During a titration, a known volume of the unknown solution is pipetted into a flask with several drops of indicator (eg. Phenolphthalein). The flask is often placed on a white mat to make the endpoint easier to see. The burette should be clamped and positioned vertically above the flask; the titrant is added and initial volume is always recorded for reference. One should add the titrant in small quantities via the stopcock. As titrations progress, the colour change that is witnessed takes longer to disappear after each occurrence, which indicates that the equivalence point is getting closer. This point is reached when a permanent colour change is seen for more than 30 seconds, however, it is very possible to add too much titrant before recording how much was added to reach the end point. Therefore, once the end point is reached, close the stopcock, measure the final volume of the titrant, and subtract it from the initial volume. This tells us how much was used to react with the analyte. After the reaction is completed, analytical methods must be implemented to determine the analyte’s concentration. 3 All calculations are based on the formula that is used to determine molar concentration (shown to the right).