Titration Explained with Simple Animations

Titration is a precise laboratory method used to determine the concentration of an unknown solution.The setup consists of a burette filled with a solution of known concentration, called the titrant, positioned above an Erlenmeyer flask.The flask contains our analyte, which is the solution of unknown concentration that we want to measure.Before we begin the titration, we add a few drops of an indicator solution to the analyte.The titration process involves carefully controlling the addition of the titrant drop by drop.After each addition, we swirl the flask to ensure proper mixing of the solutions.Remember these key points for successful titration: carefully control the addition of titrant, ensure proper mixing, and watch for any color changes in your solution.During a titration, the titrant gradually neutralizes or reacts with the analyte. Let's look at this process at the molecular level.When an acid and base react, they form water. This happens molecule by molecule until we reach the endpoint.To know when we've reached the endpoint, we use indicators that change color. Let's look at two common indicators.Phenolphthalein is colorless in acidic solutions and turns pink in basic solutions. Methyl orange changes from red in acid to yellow in base.The equivalence point occurs when we've added exactly enough titrant to react with all of the analyte. Let's see how the solution changes as we approach this point.We can track this process using a pH curve. Notice the sharp change in pH at the equivalence point.At the equivalence point, we see a dramatic change in pH with just a small addition of titrant.To calculate the unknown concentration, we'll use the balanced chemical equation.Let's start with our given information from the titration.First, we need to convert our volumes from milliliters to liters.Next, we calculate the moles of sodium hydroxide using molarity times volume.Since the balanced equation shows a one-to-one ratio between HCl and NaOH, we know they have equal moles at the endpoint.Finally, we can calculate the hydrochloric acid concentration by dividing moles by volume.Our calculation shows that the unknown HCl concentration is 0.05 molar.