A titration is a technique used in chemistry to determine the concentration of certain substances. This is done by adding to the measured sample an exact known molarity to a solution with an unknown concentration. An indicator, in this case phenolphthalein, is used to signal the completion of the reaction. The concentration can then be quantitatively determined. During any acid-base titration, the reaction will always include the neutralization between aqueous hydrogen and hydroxide ions. These ions come together to for neutral water molecules.

The titration process in this lab was used to figure out when the number of moles of acid equals the number of moles of base, the equivalence point. In this lab, we figured out that the equivalence point was when the acid, HCl, turned the lightest shade of pink possible and sustained the colour for thirty seconds when base, NaOH, was added. This light shade of pink that had to linger for at least thirty seconds also marked when the end point of the titration was reached.

The results of our lab are as follows:

Moles of NaOH: 0.00145

Moles of HCl: 0.00145

Concentration of [HCl]: 0.145

Core Competency Reflection – Thinking

Some strategies my partner and I concocted to solve and overcome a problem were to ask those around us. By asking other students who were comfortable with the lab procedure, we did not waste our given three questions. Another strategy we used was critical thinking. If something did not make sense and seemed like it did not line up, we thought through our steps and referred back to our notes and the lab procedure to guide us through our mistakes. We measured everything to best of our ability including accuracy, recording and analyzing. By thorough examination of our results, our conclusions were as accurate as possible. We made the decision to keep everything precise and start at 0.00 mL when we added our base into the buret to make the end calculations as easy as possible. The feedback we received from our teacher, Ms. Borges, was helpful when it came to minor confusions. From her advice, we changed the way we went through our procedure and everything ran smoothly in the end. For next time, I would have like to get more comfortable with half-dropping the base into the acid in the E. flask. I thought the colour was perfect in the end, as it stayed a light shade of pink for thirty seconds.

Overall, I think this lab was successful for both my partner and I.