Artifact
Curricular Competency
A titration is a technique used to determine the concentration of a substance in a solution. It involves adding a solution of a known concentration (Titrant) to a solution of the substance being analyzed. In lab 20C the titration was a regulated addition of a sodium hydroxide (NaOH) solution to a hydrochloric acid ( HCl) solution with an unknown concentration. The purpose of this lab is to titrate the hydrochloric acid and to calculate the molarity. The endpoint of a titration is the point at which the reaction between titrant and analyte is complete. It is when there is just enough titrant added to react completely with the analyte. It is at the point where the moles of acid equals the moles of base which cause a neutralization reaction. The end point is usually indicated by a color change or observable change. In the chase of lab 20C one added a PH indicator phenolphthalein. When the endpoint or equivalence point is reached the solution with the PH indicator should turn pink. The lighter the pink suggest that we have added just enough titrant to react. The darker the pink suggests to much titrant has been added and is in excess. Based off of 4 trials it was determined that the average volume was 14.00mL +/- 1.4%. Also it was found that the molarity of [HCl] was 0.140M. On top of all that the balanced equation of the reaction was NaOH + HCl -> H20 + NaCl.
Core Comptency
I can gather and combine new evidence with what I already know to develop reasoned conclusions, judgments, or plans. Lab work and follow ups offer limited information and require one to solve and find the new evidence. For example, the lab 20C on was given the molarity of NaOH and had to find and use the average volume of NaOH to find the molarity of HCl. I am able to take information presented to me and apply in both in labs and in theoretical work to solve and discover new evidence that can help prove the hypothesis. Another example, is during lab 4D I had to find the mass of the crucible and hydrate before and after the first and second heating. Taking that evidence I am able to form the formula of the hydrate. Based of the formula I was to then find the percentage of water. That new evidence allowed me to create a conclusion of how to find the empirical formula and percentage of water. Overall, I am proficient at being able to gather and combine new evidence with what I already know to develop reasoned conclusions.