Calculate the average titre, ensuring to exclude the rough titre and only include concordant results.

To find the average titre, we first need to determine the correct titre values for each trial. The titre is calculated by subtracting the initial burette reading from the final burette reading. We will then average the concordant (consistent) results, excluding the rough titre.

Step 1: Calculate the titre for each trial.

• For the "Burette rough" trial: $$\text{Titre} = \text{Final} - \text{Initial} = 13.60 - 1.00 = 12.60$$
• For the "1st" trial: $$$$