1. Although the overall objective of this experiment is to determine the molar m
ID: 546691 • Letter: 1
Question
1. Although the overall objective of this experiment is to determine the molar mass of an unknown acid, the first acid you will titrate in this experiment will be a known acid, oxalic acid. Explain why you will titrate this known acid. 2. Allana and Brenda are both doing the same experiment, which requires them to use a volumetric pipette (described in the Techniques folder) to dispense a fluid several different times. Allana's results are good and consistent, but Brenda's data vary more than they should from one trial to the next. What are two things Brenda might be doing incorrectly that would cause her this problem? 3. Waylin is doing an experiment that requires an amount of solution to be dispensed by burette. In his notebook's data section, he records that he dispensed 7.5 mL of solution. If you were Waylin's TA, what would you say to him to explain why this is worth no points? (Hint: there are two reasons for this 1. 2.Explanation / Answer
1) The details of the experiment are not furnished; however, I will make an assumption that the lab asks you to titrate an unknown acid with a standardized solution of a strong base, like sodium hydroxide, NaOH. NaOH is a secondary standard, i.e, the concentration of NaOH cannot be determined by precisely weighing out NaOH. This is due to the fact that NaOH is an ionic compound and dissociates even in the solid state; consequently, the exact concentration of NaOH is determined by titration with a primary standard. A primary standard is defined as one whose concentration doesn’t change with time. Oxalic acid is a primary standard and the exact concentration of oxalic acid can be determined by precisely weighing out oxalic acid in an analytical balance. The oxalic acid is used to titrate the supplied NaOH solution and the concentration of NaOH is determined mathematically by using the exact concentration of the oxalic acid. The NaOH is thus said to be standardized and can be used in the experiment.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.