2. Sodium salts of phosphoric acid, H3PO4, are used extensively in the preparation of buffers. The...
2. Sodium salts of phosphoric acid, H3PO4, are used extensively in the preparation of buffers. The Ka values of phosphoric acid are 7.5 x 10-3, 6.2 x 10-8, and 4.8 x 10-13. Calculate the corresponding pKa values (3). If you want the buffer to have a pH of 7.4, which of the salts do you need and why ? (2) Note : you do not need to calculate any amounts!
Homework Answers
pKa = -logKa
H3PO4/NaH2PO4 Ka1 =7.5x10-3 ; pKa = 2.1
NaH2PO4/Na2HPO4 Ka2 =6.2x10-8 ; pKa = 7.2
Na2HPO4/Na3PO4 Ka3 =4.8x10-13 ; pKa = 12.3
Buffers works best when the pKa corresponds to the desired pH.
Look up the pKa (or Ka) values associated with each acid/base conjugate pair which is closed to the desired pH = 7.4
NaH2PO4/Na2HPO4 is the right choice for the buffer of desired pH.
Add Answer to:
2. Sodium salts of phosphoric acid, H3PO4, are used extensively
in the preparation of buffers. The...
5. You have a 5.0 M solution of phosphoric acid, H3PO4 a. Write an equation three...
5. You have a 5.0 M solution of phosphoric acid, H3PO4 a. Write an equation three dissociation equations. b. As the species becomes more negative, the protons are more attracted to the species. What does this do to acid strength? C. Determine the concentration of all species in solution. Below are the needed ka values. • Ka, = 7.5 x 10-3 • Ka, = 6.2 x 10-8 • Ka, = 4.8 x 10-13 I MacBook 3013
1. Phosphoric acid, H3PO4 is a triprotic acid with pKsı = 2.14 and pKa = 7.20 and pkas 12.38. Dra...
1. Phosphoric acid, H3PO4 is a triprotic acid with pKsı = 2.14 and pKa = 7.20 and pkas 12.38. Draw the titration curve predicted for 0.1 M phosphoric acid titrated by 0.1 M NaOH. (Assume the volume of acid is 20. mL) 2. The pKb of the acetate ion is 9.25. a. Using this information, calculate the pKa of acetic acid. b. Using the Henderson-Hasselbalch equation, calculate the ratio of the concentration of acetate to acetic acid required to produce...
2) The acid-dissociation constants of phosphoric acid (H3PO4) are Kaj = = 7.5 x 10-3 Ka2...
2) The acid-dissociation constants of phosphoric acid (H3PO4) are Kaj = = 7.5 x 10-3 Ka2 = 6.2 x 10-8, and Kaz = 4.2 x 10-13 at 25.0°C. What is the pH of a 2.00 M aqueous solution of phosphoric acid?
Phosphoric acid, H3PO4, is a triprotic acid with the following acid dissociation constants: Ka1 = 7.5 × 10-3 Ka2 = 6.2...
Phosphoric acid, H3PO4, is a triprotic acid with the following acid dissociation constants: Ka1 = 7.5 × 10-3 Ka2 = 6.2 × 10-8 Ka3 = 4.2 × 10-13 Which of the following combinations would be best for preparing a pH 7 buffer? a. H3PO4 and NaH2PO4 b. H3PO4 and HCl c. Na2HPO4 and Na3PO4 d. NaH2PO4 and Na2HPO4 e. H3PO4 and Na3PO4
A buffer solution is made by adding 75.52 mL of 1.00 M phosphoric acid (H3PO4, pKa...
A buffer solution is made by adding 75.52 mL of 1.00 M phosphoric acid (H3PO4, pKa = 2.12) with 10.00 mL of 1.00 M sodium dihydrogen phosphate (NaH2PO4, pKa = 7.21). What is the pH of the buffer solution?
5. Calculate the pH at 25°C of a 0.85 M aqueous solution of phosphoric acid (H3PO4)....
5. Calculate the pH at 25°C of a 0.85 M aqueous solution of phosphoric acid (H3PO4). 5. (Ka1, Ka2, and Ka3 for phosphoric acid are 7.5 × 10−3, 6.25 × 10−8, and 4.8 × 10−13, respectively.)
4. What molar ratio of HPO4 2-to H2PO4-in solution would produce a pH of 7.0? Phosphoric...
4. What molar ratio of HPO4 2-to H2PO4-in solution would produce a pH of 7.0? Phosphoric acid (H3PO4), a triprotic acid, has 3 pKa values: 2.14, 6.86, and 12.4. Hint: Only one of the pKa values is relevant here. 5. For a weak acid with a pKaof 6.0, calculate the ratio of conjugate base to acid at a pH of 5.0. 6. Which of these compounds would be the best buffer at pH 5.0: formic acid (pKa 3.8), acetic acid...
3. Consider the following weak acids and their K, values, calculate the pK, for each acid....
3. Consider the following weak acids and their K, values, calculate the pK, for each acid. HC,H,O, - Acetic acid K. = 1.8 x 105 PK,= H,PO, - Phosphoric acid K = 7.1 x 10 PK, HCIO - Hypochlorous acid K = 3.5 x 10 pk = You want to prepare buffers at pH 2.8, 4.5 and 7.5. Which weak acid-conjugate base buffer system is the best choice for each pH from the acids listed? Write the reaction and indicate...
Phosphoric acid is a triprotic acid (Kal = 6.9 x 10-3, Ka2 = 6.2 x 10-8,...
Phosphoric acid is a triprotic acid (Kal = 6.9 x 10-3, Ka2 = 6.2 x 10-8, and Ka3 = 4.8 x 10-13). To find the pH of a buffer composed of H,PO, (aq) and HPO2 (aq), which pKa value should be used in the Henderson-Hasselbalch equation? O pK al = 2.16 OpKq2 = 7.21 O pK a3 = 12.32 Calculate the pH of a buffer solution obtained by dissolving 19.0 g of KH,PO4(s) and 30.0 g of Na, HPO4(s) in...
Llulate sodium fluoride after the addition of 0.04 mol of HCl to 1 L. of this...
Llulate sodium fluoride after the addition of 0.04 mol of HCl to 1 L. of this solution. Assume no change in volume. K. 7.1*10 the pH of a buffer solution made from 0.30 M hydrofluoric acid and 0.70 5. Calculate the pH of a 0.04 M HCI solution. Compare to the pH found in problem 4 6. Consider the following weak acids and their K values: Acetic acid Phosphoric acid Hypochlorous acid K1.8 x 10-5 Ka 7.5 x 10-3 K...
5. You have a 5.0 M solution of phosphoric acid, H3PO4 a. Write an equation three dissociation equations. b. As the species becomes more negative, the protons are more attracted to the species. What does this do to acid strength? C. Determine the concentration of all species in solution. Below are the needed ka values. • Ka, = 7.5 x 10-3 • Ka, = 6.2 x 10-8 • Ka, = 4.8 x 10-13 I MacBook 3013
1. Phosphoric acid, H3PO4 is a triprotic acid with pKsı = 2.14 and pKa = 7.20 and pkas 12.38. Draw the titration curve predicted for 0.1 M phosphoric acid titrated by 0.1 M NaOH. (Assume the volume of acid is 20. mL) 2. The pKb of the acetate ion is 9.25. a. Using this information, calculate the pKa of acetic acid. b. Using the Henderson-Hasselbalch equation, calculate the ratio of the concentration of acetate to acetic acid required to produce...
2) The acid-dissociation constants of phosphoric acid (H3PO4) are Kaj = = 7.5 x 10-3 Ka2 = 6.2 x 10-8, and Kaz = 4.2 x 10-13 at 25.0°C. What is the pH of a 2.00 M aqueous solution of phosphoric acid?
3. Consider the following weak acids and their K, values, calculate the pK, for each acid. HC,H,O, - Acetic acid K. = 1.8 x 105 PK,= H,PO, - Phosphoric acid K = 7.1 x 10 PK, HCIO - Hypochlorous acid K = 3.5 x 10 pk = You want to prepare buffers at pH 2.8, 4.5 and 7.5. Which weak acid-conjugate base buffer system is the best choice for each pH from the acids listed? Write the reaction and indicate...
Phosphoric acid is a triprotic acid (Kal = 6.9 x 10-3, Ka2 = 6.2 x 10-8, and Ka3 = 4.8 x 10-13). To find the pH of a buffer composed of H,PO, (aq) and HPO2 (aq), which pKa value should be used in the Henderson-Hasselbalch equation? O pK al = 2.16 OpKq2 = 7.21 O pK a3 = 12.32 Calculate the pH of a buffer solution obtained by dissolving 19.0 g of KH,PO4(s) and 30.0 g of Na, HPO4(s) in...
Llulate sodium fluoride after the addition of 0.04 mol of HCl to 1 L. of this solution. Assume no change in volume. K. 7.1*10 the pH of a buffer solution made from 0.30 M hydrofluoric acid and 0.70 5. Calculate the pH of a 0.04 M HCI solution. Compare to the pH found in problem 4 6. Consider the following weak acids and their K values: Acetic acid Phosphoric acid Hypochlorous acid K1.8 x 10-5 Ka 7.5 x 10-3 K...
Most questions answered within 3 hours.
-
Question Three
Suppose you as project manager are using the Waterfall
development methodology on a large...
asked 34 minutes ago -
Which statement is not true about welfare in Canada?
A.Benefits typically vary based on one's ability...
asked 1 hour ago -
Please help me with FLOWCHART and UML diagram for class,
thank you!
#include <iostream>
#include <fstream>...
asked 1 hour ago -
3. Describe the “logic circuit” of the Lac operon. Which
proteins are bound or not to...
asked 1 hour ago -
Ayesha’s adjusted gross income is $60,000 in 2019. She donated a
piece of artwork with a...
asked 1 hour ago -
For Dijkstra’s shortest path algorithm:
a. Give the Big-O time for Dijkstra’s shortest path algorithm
and...
asked 2 hours ago -
Phosphorus violates the 'octet rule' in biological molecules,
forming more covalent bonds than expected based on...
asked 2 hours ago -
A 1.3 eV electron has a 10-4 probability of tunneling
through a 2.4 eV potential barrier....
asked 2 hours ago -
What is the one ingredient that is common to being successful
with all stakeholders?
profit
trust...
asked 2 hours ago -
Write an assembly language 32 bit program that reads in lines of
text by a .txt...
asked 2 hours ago -
what is the density ( in g/L) of hydrogen gas at 29 degrees C and a...
asked 2 hours ago -
5-6. You are considering three investment alternatives for some
spare cash: Old Reliable Corporation stock (A1),...
asked 2 hours ago