How to prepare 50mM Na2HPO4/H3PO4 buffer, pH 4.5

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Discussion Overview

The discussion revolves around the preparation of a 50mM Na2HPO4/H3PO4 buffer at pH 4.5, focusing on methods and understanding of buffer solutions.

Discussion Character

  • Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant inquires about the formula for preparing the buffer and the meaning of the "/" between Na2HPO4 and H3PO4.
  • Another participant explains that the "/" indicates a buffer containing both components and suggests reading about buffer solutions, while expressing concern about the suitability of the chosen buffer for pH 4.5.
  • A participant proposes a method involving the preparation of H3PO4 followed by the addition of NaOH, presenting a chemical equation for the reaction.
  • Another participant confirms that mixing the acid and the salt solution is also a valid method for preparation.

Areas of Agreement / Disagreement

There is no consensus on the appropriateness of the buffer choice for pH 4.5, and multiple methods for preparation are discussed without agreement on a single preferred approach.

Contextual Notes

Participants express varying levels of confidence regarding the buffer's suitability and the preparation methods, with some assumptions about the reader's prior knowledge of buffer solutions.

Natsu1993
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The have to prepare the buffer but I really don't know how. Is the any formula for the buffer preparation?

Ps. Sorry but one more thing, what does the "/" between Na2HPO4 and H3PO4 mean?
 
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/ means buffer containing both Na2HPO4 and H3PO4.

I strongly suggest you start by reading about buffer solutions, for example here: https://en.wikipedia.org/wiki/Buffer_solution (but there are plenty of other resources on the web).

For pH 4.5 this is a very bad buffer choice.

Sorry to say that, but from the way you asked the question it is clear you are not qualified for the task.
 
So, I have to prepare H3PO4 and then add NaOH?

H3PO4 + 2NaOH ---> Na2HPO4 + 2H2O

Am I correct?
 
This is one of ways of doing it. You can as well mix the acid and the salt solution.
 

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