Titration Lab Report Example | Topics and Well Written Essays - 750 words

Titration - Lab Report Example In the case of the titration of NaOH with dilute HCl and dilute H2SO4 this point is marked by the sudden and stable change in the color of the base-indicator mixture following titration with the acid. This experiment will determine the volume of the acid used when the end point is reached after 0.1M sodium hydroxide is titrated with hydrochloric acid and sulphuric acid of unknown molarities using phenolphthalein indicator. While wearing safety glasses and a lab coat 100 cm3 of NaOH (aq) was collected in a large beaker. A burette was clamped firmly and filled with dilute HCl  ­(aq) until the bottom of the meniscus of the acid was on the zero line. 25.00 cm3 of the NaOH solution was pipetted (with caution) into a conical flask and then four drops of phenolphthalein indicator added. This flask was then placed on a white tile that was placed directly underneath the burette’s tap. Acid from the burette was added rapidly into the conical flask until the red colour disappeared. The volume of the acid added was noted down as the rough value. The burette was then filled again with dilute HCl (aq) to the zero mark and another 25.00 cm3 of NaOH (aq) cautiously pipetted into a second conical flask and four drops of phenolphthalein added. The acid was then added rapidly until within 2 cm3 of the reading noted earlier, at which point it was added slowly until the colour of the solution in the conical flask just disappeared. The volume of acid used was recorded. These last two steps of the experiment were repeated two more times, after which the entire experiment was repeated again, using dilute H2SO4 (aq) instead of dilute HCl (aq). In this experiment, phenolphthalein was used as the indicator. During the titration, the acid was allowed to mix with the base. In doing so, the pH values changed from basic (>7) towards 7. At the end point, the pH was neutral as this is the point when there are equal amounts of base and acid in the mixture. The chemical equations