The three pieces of equipment, A, B and C, shown are used in volumetric analysis - Leaving Cert Chemistry - Question 2 - 2012

Using C (the burette) is advisable because it allows for precise measurement of the solution being titrated, ensuring that the correct amount is delivered for accurate results.

Rinse A (the pipette) and B (the burette) by filling each with distilled (or deionized) water and letting it drain. Next, rinse A with a little of the solution that will be measured, making sure to coat the inside of the pipette before filling it to the mark. Rinse B with a small volume of the titrant solution (NaOH) it will contain, ensuring it is ready for accurate titration.

The last drop of solution must not be blown or shaken out because the pipette is designed to deliver the exact volume it measures, including the last drop. Blowing out this drop would result in delivering less than the required volume, leading to inaccuracies in measurements and affecting the results of the titration.

One other piece of equipment used in carrying out titrations is a conical flask.

A suitable indicator for this titration is phenolphthalein, which changes from colourless in an acidic solution to pink in a basic solution.

The moles of HCl used can be calculated using the concentration and volume:

$0.08 \, ext{M} \times \frac{20.0 \, \text{cm}^3}{1000} = 0.0016 \, \text{moles HCl}$.

Since the stoichiometry of the reaction is 1:1, moles of NaOH = moles of HCl = 0.0016 moles.

The concentration of NaOH can be calculated as follows:

$\text{Concentration (C)} = \frac{\text{moles}}{\text{volume (L)}} = \frac{0.0016 \text{ moles}}{0.025 \text{ L}} = 0.064 \text{ M}$.