Titration Rept.

The following should be included in your Titration Lab Report.

Purpose: Performing this lab successfully will allow us to learn an important lab technique called titration. In doing a titration we will practice neutralizing an acid with a base of known strength. At the moment of neutralization we know that Na x Va = Nb x Vb. (Where Na is the strength of the acid in normality, Va is the volume of the acid; Nb the strength of the base and Vb the volume of the base), We can use this relationship to calculate the strength of our acid. 

Procedures: Summarize these from your lab sheet.

Neutralization Theory: In this lab we neutralized an acid with a base. All neutralization reactions in general work like this:

Acid + Base ==> Salt + Water

We used an unknown strength of hydrochloric acid which we neutralized with 0.5N sodium hydroxide (our base). This reaction is:

HCl + NaOH ==> NaCl + H2O

In order for a solution to be neutral, OH- ions must be equal to the H+ ions present. So we know that:

Na x Va = Nb x Vb

In this lab we know the strength of the base and the volume of the acid. We will measure the amount of base needed to just turn the phenophthalein pink. We will then solve for the strength of our acid.

Data: The following chart summarizes the data that we gathered in lab when titrating an unknown acid with 0.5 N NaOH. (Please note these are sample data only and are not the same as any lab group actually used.)

Vol. base Norm. Base Vol. Acid Norm. Acid
 25.8 mL  0.5 N NaOH  20.0 mL  0.644 N
 25.3 mL 0.5 N NaOH  20.1 mL  0.63 N
 22.5 mL 0.5 N NaOH  19.7 mL  0.57 N
25.4 mL  0.5 N NaOH  20.0 mL 0.635 N

The average of our 3 best trials is 0.64 N for our unknown acid D.

Conclusions:We conclude that the acid D is 0.64 N HCl. We believe that trial #3 should be omitted because we know that we accidentally overshot the equivalence point and our titration flask was too bright pink.