# How does one prepare a 100ml of a 0.1M sodium phosphate buffer?

• g07l0989
In summary, to prepare a 100ml of a 0.1M sodium phosphate buffer containing 0.5M NaCl and pH 7.6, you would use either H3PO4/NaH2PO4, NaH2PO4/Na2HPO4 or Na2HPO4/Na3PO4 buffersystems, depending on the pKa values. A handbook of analytical chemistry can assist with the mathematical explanation and for the desired pH range, the NaH2PO4/Na2HPO4 system with a pH range of 6-8 and a middle value of H+=Kz2 or -logKz2=7.22 can be used. NaCl is used
g07l0989
how would you prepare a 100ml of a 0.1M sodium phosphate buffer containing 0.5M NaCl,pH7.6 using henderson hasselbach equation??what chemicals would you use n how would you go about it

Last edited:
Why do you use NaCl?

bu

cos i need the sodium ions anyway ignore the NaCL how would you do it??

Buffersystems H3PO4/NaH2PO4 or NaH2PO4/Na2HPO4 or Na2HPO4/Na3PO4

any which would give a pH of 7.6 so i ges you would have to look at the pKa to decide which to use

Last edited:
A handbook of analytical chemistry can help you with the mathematical explanation. For your pH range you can use the NaH2PO4/Na2HPO4 system range pH 6 - 8 with the middle value H+=Kz2 or -logKz2 =7.22 Greetings

thank you a lot that relly helped me thanks ciao...

## 1. How do I calculate the amount of sodium phosphate needed for a 0.1M buffer?

To prepare a 0.1M sodium phosphate buffer, you will need to use the formula C1V1 = C2V2, where C1 is the initial concentration (0.1M), V1 is the initial volume (unknown), C2 is the desired concentration (0.1M), and V2 is the desired volume (100ml). Simply rearrange the formula to solve for V1, which will give you the initial volume of sodium phosphate needed for the buffer.

## 2. What is the correct way to measure out the sodium phosphate for the buffer?

It is important to use a calibrated balance to accurately measure out the correct amount of sodium phosphate. The mass of sodium phosphate needed can be determined by multiplying the molar mass of sodium phosphate (120.08 g/mol) by the number of moles needed (0.1 mol) and converting the result to grams. Make sure to use a clean and dry weighing boat or container to hold the sodium phosphate.

## 3. Can I use any type of water to make the buffer?

No, it is important to use only high-quality water, such as deionized or distilled water, to prepare the buffer. Tap water or other types of water may contain impurities that can affect the accuracy and effectiveness of the buffer.

## 4. How do I adjust the pH of the buffer to the desired value?

The pH of a buffer can be adjusted by adding small amounts of a strong acid or base. For a sodium phosphate buffer, you can use either phosphoric acid or sodium hydroxide to adjust the pH. It is recommended to use a pH meter or indicator paper to monitor the pH and make small adjustments until the desired value is reached.

## 5. Can I store the prepared buffer for future use?

Yes, you can store the prepared buffer in a sealed container at room temperature for a few days. However, it is recommended to prepare a fresh batch of buffer for each experiment to ensure the accuracy and consistency of your results.

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