Is phosphoric acid titration curve?
Although often listed together with strong mineral acids (hydrochloric, nitric and sulfuric) phosphoric acid is relatively weak, with pKa1=2.15, pKa2=7.20 and pKa3=12.35. That means titration curve contains only two inflection points and phosphoric acid can be titrated either as a monoprotic acid or as a diprotic acid.
What is the best indicator for phosphoric acid titration?
As explained above, during titration of phosphoric acid can be used either Methyl Orange or Bromocresol Green and detect first end point around pH 4.7, or Thymolphthalein and detect second end point around pH 9.6.
How would the titration curve look if we titrated a Polyprotic acid?
The number of equivalence points in a titration curve for a polyprotic acid is equal to the number of acidic protons in the acid. Therefore, since we titrated a diprotic acid with two acidic protons, the titration curve has two equivalence points.
How does a potentiometric titration work?
Potentiometric titration belongs to chemical methods of analysis in which the endpoint of the titration is monitored with an indicator electrode that records the change of the potential as a function of the amount (usually the volume) of the added titrant of exactly known concentration.
How do you titrate phosphoric acid?
Set up the titration assembly using the stand material, the magnetic stirrer, the beaker and the burette. Put just 100 ml of distilled water into the beaker, and add 10 ml of a 10 % solution of phosphoric acid (c(H3PO4) approx. 1.1 mol/l) using the pipette.
What is potentiometric acid-base titration?
Potentiometric titration is a technique similar to direct titration of a redox reaction. It is a useful means of characterizing an acid. No indicator is used; instead the potential is measured across the analyte, typically an electrolyte solution.