Determining The Titration Of An Unknown Solution

Titration is a method used to help determine the concentration of an unknown solution (the analyte) by using a solution of known concentration (the titrant).1 In medicine, titration helps doctors determine unknown concentrations of substances in the blood or urine, and it is useful in determining the proper dosage of medication. Titration can determine fat and water contents, and unknown concentrations of vitamins. With food, titration can be used to determine whether cheese or wine is adequately aged for delivery.2 The objectives of this experiment are to successfully perform an accurate acid-base titration, determine moles using molarity and volume, and use the total mass and moles of hydronium to determine the equivalent mass. Students will
The color change can occur quickly, so be ready to stop the valve. In the “rough” section of the report sheet, record the initial, final and net volume (Vfinal-Vinitial). Refill the burette with sodium hydroxide until it reaches the 0.00 mL mark, and allow some to run through the burette tip into the titrated solution. Repeat steps 9 through 11, using the remaining two flasks, marking them “trial 1” and “trial 2.” To estimate the amount of titrant that will be need use the equation shown below. Doing this will allow you to titrate quickly until you get close to the estimated value, then slowly for an accurate reading.
Estimated trial net volume = (rough net volume)/(rough acid mass) x trial acid mass To get the estimated final volume, take the initial volume from step 13, and add the estimated net volume for “trial 1.” Quickly titrate until the volume is about 5 mL away from the estimated final volume for “trial 1.” After, titrate the solution slowly, one drop at a time, constantly swirling until the solution changes to a light pink
With those results in mind, for the two trials to be completed, the goal was to achieve a lighter pink color change. When performing “trial 1,” the sodium hydroxide was titrated rapidly until it was close to the estimated final volume, 41.6, and a light pink color was produced once it reached 42.6 mL. After converting the net volume from mL to L, this value was multiplied by the molarity of sodium hydroxide to get the moles of OH-. The same calculations were performed to find the moles of H3O+, which was the same value as the moles of OH-, 0.00414 moles. Then, the equivalent mass of the acid was determined by taking the mass of the acid, and dividing it by the moles of OH-, producing an equivalent mass of 60.4 grams per