Practicals - AS Level

Question 1

What is the method for making a standard solution?

Answer 1

1) Weigh the solid by difference
2) Place the solid in a beaker and dissolve it with ~100cm³ of distilled water
3) Transfer the solution to a 250cm³ volumetric flask
4) Rinse the equipment into a volumetric flask
5) Make the solution up to the mark using a pipette. The bottom of the miniscus should be on the line.
6) Put on the lid and invert several times

Question 2

What is the method for carrying out a titration?

Answer 2

1) Rinse all glasswear with distilled water and the solution that will be used
2) Measure 25cm³ of the standard solution with a pipette filler and put into the conical flask
3) Add 3-4 drops of indicator and place the flask onto a white tile
4) Using a funnel, fill the burette with acid until the 0 mark with the bottom of the meniscus on this line
5) Complete a rough titration, trying to identify the end point
6) Repeat the experiment, adding acid drop by drop until the end point. Rinse the conical flask between titrations with distilled water.
7) Record results in a table and calculate the mean titre