Where Should the Standard Solution Go in an Acid-Base Titration?

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Discussion Overview

The discussion revolves around the placement of the standard solution in an acid-base titration setup, specifically whether it should be in the buret or the Erlenmeyer flask. Participants explore the implications of each arrangement in the context of introductory chemistry lab practices.

Discussion Character

  • Homework-related
  • Debate/contested

Main Points Raised

  • One participant states that in their lab setup, the acid with unknown concentration is in the Erlenmeyer flask and the base with known concentration is in the buret, questioning if this is standard practice.
  • Another participant mentions their consistent practice of placing the known solution in the buret but does not provide a strong rationale for this choice.
  • A participant seeks clarification on whether "titrant" refers exclusively to the solution in the buret or if it can also denote the solution of known concentration.
  • One participant argues for placing the standard solution in the flask, citing the accuracy of pipetting over burette measurements, but acknowledges that the overall accuracy is ultimately determined by the less accurate measurement from the buret.
  • This same participant notes that detecting a color change may be more effective when the indicator changes from colorless to pink rather than the reverse.

Areas of Agreement / Disagreement

Participants express differing opinions on the placement of the standard solution, with no consensus reached on the best practice. The discussion remains unresolved regarding the implications of each setup.

Contextual Notes

Participants express uncertainty about the terminology used in titrations, particularly the definition of "titrant," and the accuracy of measurements from different apparatuses. There are also assumptions about the visibility of color changes in indicators that are not fully explored.

jumbogala
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Homework Statement


Hi everyone. I'm teaching introductory chemistry this semester, but I don't have much of a chem background.

We are about to start acid base titrations. Does the standard solution of known concentration go in the buret tube or the erlenmeyer flask? Does it matter?

Homework Equations

The Attempt at a Solution


In my lab, the acid has the unknown concentration, while the base's concentration is known. I have it set up so that the acid is in the erlenmeyer flask and the base is in the buret tube.

This is convenient because the indicator is colorless in the acid but pink in the base. However, would there ever be a situation where solution with the known concentration would be in the erlenmeyer flask?
 
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I have always put known into the burette. Not that I don't know any serious arguments telling why we should do it this way.
 
Last edited:
Good to know, thank you! One more thing - is "titrant" always the solution of known concentration, or just the name for the solution that goes in the buret? It's hard to find a clear answer online.
 
Other things being equal I would put the standard in the flask. Because the pipettes sampling will be more accurate than the burette measurement I prefer the feeling that there is one thing there that I know as accurately as possible against which I am measuring my unknown. But it is ridiculous of me, because the final accuracy will just depend on then,east accurate part - then burette. Nothing to choose really.

Your point is more important - you are likely to detect a colour appearance better than its disappearance.
 

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