Curricular Competency Explanation

Lab 20C’s purpose was to titrate a mystery hydrochloric acid solution and 0.100 M sodium hydroxide and from there determine the molarity of the hydrochloric acid. A titration is a special neutralization reaction wherein a specific amount of acid is mixed with phenolphthalein and a base is placed in a burette and is slowly mixed with the acid until is changes colour. Titrations allow you to discover the volumes needed for a neutralization. So, the students titrated NaOH into 10.00±0.05 mL HCl and phenolphthalein solution. After four trials it was determined that 14.12 mL ±1.4% of NaOH was needed to neutralize the solution. This was determined when the titration reached the endpoint, when the colour turned pink from its original clear state. The endpoint of a titration is when the colour changes ever so slightly because this means that the solution is pretty much neutralized, with just a slight bit more base. With that number, they calculated 1.412×10-3±1.4% moles of NaOH which allowed the students to determine the molarity of the HCl solution which is 0.412 M. A systematic error occurred because the students could only record the neutralization through qualitative observations. And a human error occurred because when the students added a half drop of NaOH by mistake rather than a quarter drop. Due to this, the true average amount of NaOH may be lower than the results obtained in this lab.

Core Competency Reflection

I think I did a good job collaborating in this lab. For example, this was a partner lab, so my partner evenly split the responsibilities of this lab by discussing prior who will do what. We both set up the lab and then we took turns titrating and recording answers. However, during this lab, we had a few questions. Some we were able to effectively communicate with eachother to solve, but others were more difficult. So, we also collaborating with neighbouring groups to come up with solutions. Also, I tried to actively listen so that we could collaborate even better. The picture shown above is of one of our titrations. By applying the strategies I mentioned we were able to successfully complete this lab. One thing I could work on is slowing down when I talk so that I will be able to communicate even better.