How to Calculate the Endpoints of Titration

Prepare a Buret

• 1

  Fill a buret with titrant solution using either a plastic funnel of disposable pipet. Coat its side with solution, then allow it to drain up to three times.

• 2

  Remove any air bubbles near the buret's tip by tapping its side until the solution flows.

• 3

  Rinse the tip of the buret with water and dry it carefully with paper towel. Place an Erlenmeyer flask underneath it to collect the solution.

• 4

  Record the initial volume reading at the bottom of the meniscus, or curved upper surface, in your lab notebook. Predict your expected endpoint volume.

• 5

  Turn the buret's stopcock towards you to allow the solution to flow down to the flask. Observe the instant, yet fading color change as it hits the solution.

Perform the Titration

• 6

  Add drops of the analyzed solution in the Erlenmeyer flask. Add a stirrer to the bottom of the flask, then add indicator to the solution as well.

• 7

  Slowly add drops of titrant as your approach the endpoint, which is when the color begins to brighten.

• 8

  Partially drop the titrant by rapidly spinning the stopcock, if necessary. Rinse the sides of the flask with water to avoid overtitrating.

• 9

  Record the final volume in the lab notebook when your solution is a pale pink or bluish color.

• 10

  Subtract the final endpoint from the initial endpoint. Note the difference between your observe and predicted values for the volume of titration. Calculate the reactant's number of moles using stochiometry.

• 11

  Use pH paper to test the acidity of the titrant. Use your pH and volume to calculate the reactant's number of moles using stochiometry.