[exec]

A titration experiment is carried out and three values of reading are taken from the burette. (I don't have a scanner so I can't put on the pic.)

Suppose that the readings of the solution used are Ai, Af, Bi, Bf, Ci, Cf where Ai means the initial reading for the first titration and f for final reading, then a table is to be filled.

            Rough               Accurate
                     First Titration      Second Titration
Final Reading                      Af                Bf         
Initial Reading                       Ai                 Bi   
Volume of solution used               X                 Y   

(i)What do I fill in for the 'Rough' column?

(ii)Then, calculate the average titre value. What is a titre value?


(ii) Is the average titre value the average volume of the solution needed, that is the average of X and Y?

[Dan]

(i)What do I fill in for the 'Rough' column?

When doing a titration, you often do a quick one first to get a rough idea of how much of the solution from you burette is needed. This is so that you don't spend ages adding a large volume.

Say, for example, you need 25.7 mL of your solution from your burette (but you don't know that yet), the the first time you do it you would add the solution quickly and might get a rough volume of 27 mL. Then you do it slowly, knowing that you can add the first 20 mL quickly, and then slow down to get an accurate end point by adding the solution dropwise.

(ii)Then, calculate the average titre value. What is a titre value?


(ii) Is the average titre value the average volume of the solution needed, that is the average of X and Y?

The titre value is the volume you needed to add to reach the end point. You work this out from your initial and final burette readings. You should take an average from several accurate  titrations to determine your average titre value.