Required Practicals - Titrations

Question 1

What is the goal of the titration practical?

Answer 1

Determining the:
-reacting volumes of a strong acid and a strong alkali by titration
-concentration of one of the solutions in mol/dm3 and g/dm3 from the reacting volumes and the known concentrations of other solutions.

Question 2

What is the apparatus list for the titration practical?

Answer 2

-25cm3 volumetric pipette and pipette filler
-burette
-a small funnel
-a clamp and clamp stand
-250cm3 conical flask
-white tile
-dilute sulfuric acid, concentration unknown
-0.1 mol/dm3 sodium hydroxide solution
-phenolpthalein indicator

Question 3

What is the method for the titration practical?

Answer 3

-Use the pipette and pipette filler to put exactly 25cm3 sodium hydroxide solution into the conical flask.
-Put the flask on a white tile
-Clamp the burette vertically in the clamp stand.
-Close the burette tap.
-Use the small funnel to carefully fill the burette with dilute sulfuric acid. Before it completely fills put a small beaker underneath the tap, gently open it to allow acid to fill the tap, before closing again amd filling the burette to the 0.00cm3 line. Remove the funnel.
-Put 5-10 drops of indicator into the conical flask. Swirl the flask to mix and put under the burette on top of the tile. The contents of the flask will go pink.
-Carefully open the burette tap so that 10cm3 of sulfuric acid slowly flows into the flask. Constantly swirl the flask when adding the acid. Then add the acid drop by drop until you see a permanent colour change from pink to colourless in the flask.
-You need to be able to shut the tap immediately after a single drop of acid causes the colour to become permanently colourless.
-Read the burette scale carefully and record the volume of acid added to 2 decimal places.
-Repeat twice more and record the results in the table.