33 10 4 mol of KHP 333 10 4 mol of NaOH Molarity of NaOH 00129 M NaOH 2

33 10 4 mol of khp 333 10 4 mol of naoh molarity of

This preview shows page 4 - 5 out of 5 pages.

Moles of KHP = = 3.33 * 10 -4 mol of KHP= 3.33 * 10 -4 mol of NaOH Molarity of NaOH = = = 0.0129 M NaOH 2. Concentration (M) of phosphoric acid in cola sample M 1 V 1 = M 2 V 2 Moles of acid = Moles of base at the 1 st Equivalence Point M of H 3 PO 4 = = = 0.00530 M of H 3 PO 4 3. K a1 calculated non-graphically using Ka expression K a1 = = = = .00876 4. Percent acid dissociation Percent dissociation H 3 PO 4 = * 100% = * 100 % = 70.2 % III. DiscussionIn this experiment surrounding titrating a sample of degased Cola, multiples chemical principles are utilized and touched on. An interesting part of the experiment is the titration of a polyprotic acid, H3PO4, which is a large component of coke. Also, complex calculations of Kavalues specific to each loss of the proton in the stages of neutralizing H3PO4 also played a huge role in this specific lab. In table 1, the NaOH used later on for the titration is standardized. Since KHP and NaOH have a 1:1 ratio when in reaction, the exact mole and molarity of the NaOH can be found by simply finding the exact mass of KHP used and the amount of deionized water used to make the KHP solution. The average of the runs of titration shows that the NaOH has a molarity of around 0.01145 M. After standardizing the NaOH, it can be used as the titrant to find the molarity of the analyte, the degassed cola. The main point of this titration of coke is to find the exact 1stand 2ndKavalues by looking at the titration graph created with the aid of the pH electrode of LabQuest. To find these equivalence points, the first derivative of the graph of pH vs volume of NaOH used is also found. The equivalence
Image of page 4
Image of page 5

You've reached the end of your free preview.

Want to read all 5 pages?

  • Fall '12
  • SOPER
  • Molarity, Mole, pH, Equivalence point, H3PO4, equivalence points

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture