
Chemistry: Principles and Reactions
8th Edition
ISBN: 9781305079373
Author: William L. Masterton, Cecile N. Hurley
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
How do I set up the equation to figure out the concentrations of HA and OH-?

Transcribed Image Text:Strong base is dissolved in 625 mL of 0.400 M weak acid (Ka 4.48 x10) to make a buffer with a pH of 4.08.
Assume that the volume remains constant when the base is added
Calculate the pKa value of the acid and determine the number of moles of acid initially present.
ncorrect.
Use the volume and concentration
in the question to find moles.
Number
Number
pK,434
2.5
mol HA Molarity is the number of moles
per liter
When the reaction is complete, what is the concentration ratio of conjugate base to acid?
Number
НА
How many moles of strong base were initially added?
Number
mol OH
Expert Solution

Trending nowThis is a popular solution!
Step by stepSolved in 3 steps with 1 images

Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.Similar questions
Fifty cm3 of 1.000 M nitrous acid is titrated with 0.850 M NaOH. What is the pH of the solution (a) before any NaOH is added? (b) at half-neutralization? (c) at the equivalence point? (d) when 0.10 mL less than the volume of NaOH to reach the equivalence point is added? (e) when 0.10 mL more than the volume of NaOH to reach the equivalence point is added? (f) Use your data to construct a plot similar to that shown in Figure 14.10 (pH versus volume NaOH added).
arrow_forward
Which of these buffers involving a weak acid HA has the greater resistance to change in pH? Explain your answer. (i) [HA] =0.100 M = [A] (ii) [HA] = 0.300 M = [A]
arrow_forward
A buffer is prepared by dissolving 0.062 mol of sodium fluoride in 127 mL of 0.0399 M hydrofluoric acid. Assume no volume change after NaF is added. Calculate the pH of this buffer.
arrow_forward
K4 for acetic acid is 1.7 105 at 25C. A buffer solution is made by mixing 52.1 mL of 0.122 M acetic acid with 46.1 mL of 0.182 M sodium acetate. Calculate the pH of this solution at 25C after the addition of 5.82 mL of 0.125 M NaOH.
arrow_forward
Repeat the procedure in Exercise 61, but for the titration of 25.0 mL of 0.100 M pyridine with 0.100 M hydrochloric acid (Kb for pyridine is 1.7 109). Do not calculate the points at 24.9 and 25.1 mL.
arrow_forward
A 1.0L buffer is made at 25°C that consists of 0.80 mol of a weak acid HA and 0.80 mol of its conjugate base A-. The acid ionizarion constant is Ka= 1×10^-4. To this buffer solution 0.80 mol NaOH is added. Assuming that the volume change due to the added NaOH is negligible, calculate pOH in the resulting solution.
arrow_forward
One drop, 0.200 cm3, of 1.00 mol dm-3 of aqueous sodium hydroxide, NaOH, solution is added to 25.0 cm3 of a phosphate buffer that is 0.040 mol dm-3 in KH2PO4(aq) and 0.020 mol dm-3 in K2HPO4(aq). Calculate the resulting pH of the solution given that the second acid dissociation constant, pKa2, for phosphoric acid is 7.21.
arrow_forward
Consider a buffer solution that contains 0.55 M NH2CH2CO2H and 0.35 M NH2CH2CO2Na. pKa(NH2CH2CO2H)=9.88.
a. Calculate the change in pH if 0.155 g of solid NaOH is added to 250 mL of this solution.
b. If the acceptable buffer range of the solution is ±0.10 pH units, calculate how many moles of H3O+ can be neutralized by 250 mL of the initial buffer.
c. Calculate its pH.
arrow_forward
What will be the appropriate pH of a buffer prepared by mixing 100 ml of 0.1 M Na2HPO4 and 100 ml of 0.1 M NaH2PO4? (For H3PO4, pKa1 = 2.1; pKa2 = 6.8; pKa3 = 12.5) Ans in 2 significant figures
arrow_forward
A buffer is prepared using lactic acid (HLac) and sodium lactose (NaLac). 0.300 dm3 of the 0.500 mol.dm3 HLac solution is mixed with 0.300 dm3 of 0.300 mol.dm3 NaLac solution to prepare the buffer. Ka for lactic acid is 1.4 x 10-4 . Calculate the PH of the lactic acid before it is mixed with the NaLac to form a buffer
Calculate the PH of the buffer
What will the PH of the buffer solution be after 5.0 cm3 of 0.200mol.dm3 NaOH has been added to only 100 cm3 of this buffer?
arrow_forward
When titrating a 25 mL solution of 0.20M CH3COOH with 0.10M KOH, you realize you forgot to add an indicator initially. You've added 10 mL of KOH to the flask of acid. Ka of CH3COOH = 1.8 x 10^-5
1) Calculate the pH at this point
2) What color would your solution be if you add 40 mL KOH more. And a few drops of clorophenol blue indicator at this point. Why?
arrow_forward
1). You are running an experiment and need to keep your solution within a certain pH range: 3.5 +/- 1pH unit.
Choose a buffer system (e.g. a conjugate acid/base) with a pKa in the appropriate range..
Assuming you have 0.2M stock solutions of the acid and conjugate base, calculate the L of each need to make 400 mL of buffer.
Describe clearly your protocol for making the buffer solution to the desired pH.
Calculate pH for the following.
Add 100 mL of 0.100 M HCl to pure water
Add 100 mL of 0.100 M HCl to the 400 mL of buffer you made
Add 100 mL of 0.100 M NaOH to pure water
Add 100 mL of 0.100 M NaOH to the 400 mL of buffer you made
arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you

Chemistry: Principles and Reactions
Chemistry
ISBN:9781305079373
Author:William L. Masterton, Cecile N. Hurley
Publisher:Cengage Learning

Chemistry: Principles and Practice
Chemistry
ISBN:9780534420123
Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer
Publisher:Cengage Learning

General Chemistry - Standalone book (MindTap Cour...
Chemistry
ISBN:9781305580343
Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Publisher:Cengage Learning

Chemistry: An Atoms First Approach
Chemistry
ISBN:9781305079243
Author:Steven S. Zumdahl, Susan A. Zumdahl
Publisher:Cengage Learning


Chemistry: Principles and Reactions
Chemistry
ISBN:9781305079373
Author:William L. Masterton, Cecile N. Hurley
Publisher:Cengage Learning

Chemistry: Principles and Practice
Chemistry
ISBN:9780534420123
Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer
Publisher:Cengage Learning

General Chemistry - Standalone book (MindTap Cour...
Chemistry
ISBN:9781305580343
Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Publisher:Cengage Learning

Chemistry: An Atoms First Approach
Chemistry
ISBN:9781305079243
Author:Steven S. Zumdahl, Susan A. Zumdahl
Publisher:Cengage Learning
