HomeworkLib
Question

3). I need to make a 0.50M Tris buffer with a pH of 8.75. I have access to Tris (a weak acid) and the sodium salt of Tris (thThe Ka of Tris is 8.5x10-9 and the pKa of Tris is 8.07. What are the [HA] and [A-] concentrations of this 0.50M buffer at pH 8.75?

science   chemistry   
0 0
Add a comment Improve this question Transcribed image text
Next > < Previous
Sort answers by oldest

Homework Answers

Answer #1

Solution-

pH= pKa + log(base/acid)

=>8.75= 8.07 + log(base/acid)

=> log(A-/HA) = 0.68

=> (A-/HA) 10^0.68 = 4 .786301

=> (A-)=  4 .786301*(HA)

=>concentration of buffer = 0.5M

So (A-)+(HA)= 0.5

4 .786301*(A-)+(HA)= 0.5

5.786301*(HA)= 0.5

(HA)= 0.5/5.786301

=0.086411

=(A-)= 4.786301*(HA)

=4.786301*0.086411

=0.413589

(HA)= 0.0864

(A-)=0.414 M

0 0
Add a comment
Know the answer?
Add Answer to:
The Ka of Tris is 8.5x10-9 and the pKa of Tris is 8.07. What are the...
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. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions

  • 3). I need to make a 0.50M Tris buffer with a pH of 8.75. I have...

    3). I need to make a 0.50M Tris buffer with a pH of 8.75. I have access to Tris (a weak acid) and the sodium salt of Tris (think A-). The Ka of Tris is 8.5x10-9 and the pKa of Tris is 8.07. What are the [HA] and [A-] concentrations of this 0.50M buffer at pH 8.75?   Part A: [HA] = _____

  • 3). I need to make a 0.50M Tris buffer with a pH of 8.75. I have...

    3). I need to make a 0.50M Tris buffer with a pH of 8.75. I have access to Tris (a weak acid) and the sodium salt of Tris (think A-). The Ka of Tris is 8.5x10-9 and the pKa of Tris is 8.07. What are the [HA] and [A-] concentrations of this 0.50M buffer at pH 8.75?   Part B: [A-] = _____

  • I need to make a 0.50M Tris buffer with a pH of 8.75. I have access...

    I need to make a 0.50M Tris buffer with a pH of 8.75. I have access to Tris (a weak acid) and the sodium salt of Tris (think A-). The Ka of Tris is 8.5x10-9 and the pKa of Tris is 8.07. What are the [HA] and [A-] concentrations of this 0.50M buffer at pH 8.75? Part B: [A-] = _____

  • Which of the following compounds would make the best buffer at pH 7.5? Acetic acid, pKa=...

    Which of the following compounds would make the best buffer at pH 7.5? Acetic acid, pKa= 4.76 N-tris(hydroxymethyl) methylglycine (Tricine), pKa = 8.15 N-2-hydroxyethylpiperazine-N’-ethansulfonic acid, pKa2= 7.6 Glycine, pKa2= 9.9 Tris(hydroxymethyl)aminomethane (Tris), pKa = 8.3 I believe 3 is the correct answer and therefore I am trying to answer the below question with this information. Using the answer that you selected from question 1 above: a. Explain how you would make the buffer starting with 1M HA and 1M A-...

  • Part A Tris[tris(hydroxymethyl)aminomethane] is a common buffer for studying biological systems. (Ka = 5.01 × 10−9...

    Part A Tris[tris(hydroxymethyl)aminomethane] is a common buffer for studying biological systems. (Ka = 5.01 × 10−9 and pKa = 8.3) (a) Calculate the pH of the Tris buffer after mixing 13.5 mL of 0.15 M HCl solution with 25.0 mL of 0.10 M Tris. (b) This buffer was used to study an enzyme-catalyzed reaction. As a result of the reaction, 0.00017 mol of H+ was produced. What is the pH of the buffer at the end of the reaction? (c)...

  • A buffer solution has pH=5 and pKa=5.3. a.What is the ratio of the weak acid concentration...

    A buffer solution has pH=5 and pKa=5.3. a.What is the ratio of the weak acid concentration to its conjugate base that is needed to make a buffer of the given pH, [HA (aq)]/[A ̅ (aq)]? b.Propose what concentrations of acid and base you need to achieve that ratio?

  • The pH of a buffer is calculated by using the Henderson-Hasselbalch equation: pH=pKa +log[Base]/[Acid] Part A: What...

    The pH of a buffer is calculated by using the Henderson-Hasselbalch equation: pH=pKa +log[Base]/[Acid] Part A: What is the pH of a buffer prepared by adding 0.809mol of the weak acid HA to 0.406mol of NaA in 2.00 L of solution? The dissociation constant Ka of HA is 5.66

  • 1. What is the pH of a solution which is 0.025 M in weak base and...

    1. What is the pH of a solution which is 0.025 M in weak base and 0.039M in the conjugate weak acid (Ka = 7.1 × 10-6)? 2. A buffer solution is made using a weak acid, HA , that has a pKa of 5 . If the pH of the buffer is 8 , what is the ratio of [A−] to [HA] ? 3.A buffer solution is made using a weak acid, HA . If the pH of the...

  • 20. You need to prepare an acetate buffer of pH5.24from-a: 0.810Macetic acid solution and a 2.29MKOHsolution....

    20. You need to prepare an acetate buffer of pH5.24from-a: 0.810Macetic acid solution and a 2.29MKOHsolution. If you have 880mL of the acetic acid solution, how many milliliters of the KOHsolution do you need to add-to- make a buffer of pH95.24? The pKa of acetic acid is 4.76.1 T mLmLT 21.-1f-a-buffer solution-is-0.450.M-in-a-weak-acid-(Ka=7.3x10^-6)-and-0.110-M-in-its-conjugated base. what-is-the-ph Ph=1 13.A monoprotic weak acid, HAHA, dissociates in water according to the reactionſ HA(aq)---H-(aq)+A-(aq)HA(aq)---H+(aq)+A-(aq) The equilibrium concentrations of the reactants and products are [HAl=0.290M[ [H-]=2.00X10-4M. and...

  • help with 5 and 6 please 5. Choose the effective pH range of a HF/Naf buffer. For HF, Ka = 3.5 x 10-4 6. If a small...

    help with 5 and 6 please 5. Choose the effective pH range of a HF/Naf buffer. For HF, Ka = 3.5 x 10-4 6. If a small amount of a strong acid is added to buffer made up of a weak acid, HA, and the sodium salt of its conjugate base, NaA, the pH of the buffer solution does not change appreciably because a) the Ka of HA is changed. b) the strong acid reacts with Ato give HA, which...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT