STRONG ACID VERSUS STRONG BASE

Acid-base titration that involves strong acid versus strong base, both the titrant and the analyte are completely ionized. The examples acid-base titrations of this type are titration between hydrochloric acid with sodium hydroxide or sulfuric acid with potassium hydroxide. The reaction and the titration curve between 0.1 M NaOH as titrant and 0.1 M HCl as analyte are describe bellow :

The H+ and OH- combine to form H2O and the other ions Na+ and Cl- remain unchanged so the net result of neutralization to a neutral solution of NaCl. The titration curve is constructed by plotting the pH of the solution as the function of the titrant added.

• In the beginning of titration there is only 0.1 M HCl so the initial pH is 1.0. to count the concentration of the H+ we use [H+] = [HCl initial]
  
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• When the 0.1 M NaOH began to add somepart of the H+ is reacted with OH- to yield H2O. So the concentration of H+ gradually decreases and the pH would be raised. The H+ concentration is calculated by [H+] = [HCl remaining]
  
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• When the equivalence point is approached (the point at which a stoichiometric reaction is complete), a neutral solution of NaCl with pH would be 7 is produced.
  
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• As we continue the the concentration of OH- rapidly increases , we then have a solution of NaOH plus NaCl. The OH- concentration is calculated with [OH-] = [excess titrant]