Principle

Phosphoric acid and sodium hydroxide are to be used to give an
example of a titration of a polyvalent acid with a strong base.

Tasks


Measure the alteration of the pH value during a titration of an
aqueous solution of phosphoric acid with a 0.1 molar sodium
hydroxide solution at constant temperature using the Cobra4
system.

From the titration curve read the equivalence points and pKa
values.

Determine the concentration of the acid.


What you can learn about


Phosphoric acid

Sodium hydroxide

Polyvalent acid

pKa values

Proteolysis

pH value



Necessary accessories


Precision balance 620g/0.001g