Question

a) Which of the two of the following compounds would you mix to make a buffer...

a) Which of the two of the following compounds would you mix to make a buffer of pH 7.45 phosphoric acid (FM=98.00), sodium dihydrogen phosphate (FM=119.98), disodium hydrogen phosphate (FM=141.96), or sodium phosphate (FM=163.94)?

b) If you wanted to prepare 1.pp L of buffer with a total phosphate concentration of 0.0500M, how man grams of the selected compounds would you mix together?

c) If you did what you calculated in part (b), you would not get a pH of exactly 7.45. Explain exactly how you would really prepare the buffer in the lab.
Science   Chemistry   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

question a

Which of the two of the following compounds would you mix to make a buffer of pH 7.45 phosphoric acid (FM=98.00), sodium dihydrogen phosphate (FM=119.98), disodium hydrogen phosphate (FM=141.96), or sodium phosphate (FM=163.94)?

a) NaH2PO4

and

Na2HPO4

===============================================================================================================================================================
b) If you wanted to prepare 1.pp L of buffer with a total phosphate concentration of 0.0500M, how man grams of the selected compounds would you mix together?

(answer

4.55 g Na2HPO4 + 2.15 g NaH2PO4

==========================================================================
(c

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
You need to prepare a buffer for biochemistry lab. The required solution is 0.5Msodium phosphate, pH...
You need to prepare a buffer for biochemistry lab. The required solution is 0.5Msodium phosphate, pH 7.0. Use the Henderson-Hasselbalch equation to calculate the number of moles and grams of moobasic sodium phosphate ( NaH2PO4) and dibasic sodium phosphate ( Na2HPO4) necessary to make 1 liter of solution. The pKa for this buffer is 7.21
Phosphoric acid is a triprotic acid with the following pKa values: pka1= 2.148 pka2= 7.198 pka3=...
Phosphoric acid is a triprotic acid with the following pKa values: pka1= 2.148 pka2= 7.198 pka3= 12.375 You wish to prepare 1.000 L of a 0.0300 M phosphate buffer at pH 7.680. To do this, you choose to mix the two salt forms involved in the second ionization, NaH2PO4 and Na2HPO4, in a 1.000 L volumetric flask and add water to the mark. What mass of each salt will you add to the mixture? What other combination of phosphoric acid...
if you were asked to make up a pH=6.86, 0.1M phosphate buffer, how would you do...
if you were asked to make up a pH=6.86, 0.1M phosphate buffer, how would you do this? Using the henderson-hasselbach equation, plug in the pH and the Pka for sodium phosphate monobasic (6.86) for this situtation, what is the log(A-/HA)=
Starting with two stock buffer solutions (A and B) listed below, describe how you would mix...
Starting with two stock buffer solutions (A and B) listed below, describe how you would mix them together to obtain the solutions i and ii. Write your answers to 3 significant figures. i) 400 mL of 0.35 M NaCl, 10 mM Tris buffer (pH 8.0) ii)600 mL of 0.9 NaCl, 10 mM Tris buffer (pH 8.0). Stock buffer A: 3 M NaCl, 10 mM Tris buffer (pH 8.0) and stock buffer B: 0.1 M NaCl, 10 mM Tris buffer (pH...
1. Show the calculations required for preparing the buffers in this exercise. The pKa values for...
1. Show the calculations required for preparing the buffers in this exercise. The pKa values for H3PO4 are 2.15, 6.82, 12.32. Note that you’ll be using the pKa value of 6.82. Why? Method 1 a. Calculate the grams of NaH2PO4*H2O needed to prepare 100.0 mL of a 100mM solution. b. Calculate the amount of 1.00M NaOH you expect to add to adjust the pH of your NaH2PO4 solution to 7.0. Method 2 c. Using the Henderson-Hasselbalch equation, calculate the g...
Given the following list of common buffer systems available to you in your lab, how would...
Given the following list of common buffer systems available to you in your lab, how would you prepare a system with a pH of 7.70? HEPES pKa = 7.56 HEPPS pKa = 7.96 TRIS· HCl pKa = 8.07 A.Using HEPES solution, add NaOH to raise the pH to 7.70 B.Using HEPES solution, add HCl to lower the pH to 7.70 C.Using HEPPS solution, add HCl to lower the pH to 7.70 D.Using HEPPS solution, add NaOH to raise the pH...
1.) You will work with 0.10 M acetic acid and 17 M acetic acid in this...
1.) You will work with 0.10 M acetic acid and 17 M acetic acid in this experiment. What is the relationship between concentration and ionization? Explain the reason for this relationship 2.) Explain hydrolysis, i.e, what types of molecules undergo hydrolysis (be specific) and show equations for reactions of acid, base, and salt hydrolysis not used as examples in the introduction to this experiment 3.) In Part C: Hydrolysis of Salts, you will calibrate the pH probe prior to testing...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT