5. A buffer is made by mixing 1.250 mol formic acid, HCOOH, with 0.750 mol sodium formate, HCOONa in enough water for a total volume of 1.00L. The Ka of formic acid is 1.87 x 10-4 a. What is the pH of this buffer? b. If 0.075 mol HCI is added to this buffer, what is the pH of the resulting buffer? (assume no volume changes) c. If 0.055 mol NaOH is added to this buffer, what is the pH of the resulting buffer? (Assume no volume changes)

5. A buffer is made by mixing 1.250 mol formic acid, HCOOH, with 0.750 mol sodium formate, HCOONa in enough water for a total volume of 1.00L. The Ka of formic acid is 1.87 x 10-4 a. What is the pH of this buffer? b. If 0.075 mol HCI is added to this buffer, what is the pH of the resulting buffer? (assume no volume changes) c. If 0.055 mol NaOH is added to this buffer, what is the pH of the resulting buffer? (Assume no volume changes)

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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Part 1: A buffer system is set up with [HA] = 0.550 M and [A-] = 0.460 M in 1.0 L of aqueous solution. If pKa = 6.10, what is the pH of the buffer solution? Part 2: To the original buffer solution, what is the pH of the buffer solution after adding in 0.0500 mol of HBr (assume no volume change)? Part 3: To the original buffer solution, what is the pH of the buffer solution after adding in 0.0400 mol of KOH (assume no volume change)?
Based on Ice and aka expression determine the pH of the solution.
A chemistry graduate student is given 300. mL of a 0.20M hydrocyanic acid (HCN) solution. Hydrocyanic acid is a weak acid with K. ,=4.9 × 10 -10 What mass of KCN should the student dissolve in the HCN solution to turn it into a buffer with pH =9.11? You may assume that the volume of the solution doesn't change when the KCN is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits. alo Ar Ox10 ? 圖
A buffer solution contains 0.50 mol of acetic acid and 0.50 mol of sodium acetate in 1.0 L of solution. a) What is the pH of the solution? b) 25 mL of the solution is mixed with 75 mL of water. What is the new pH? c) 25 mL of the original solution is mixed with 25 mL of 0.10 M HCl. What is the new pH?
a. You want to prepare 1.00 L of a buffer solution with a pH of 3.5. You are given an 0.45 M solution of nitrous acid, HNO2, and an 0.68 M solution of NaOH. What volume of each of these solutions must be mixed in order to get the desired buffer solution? Use the simultaneous equations method to solve this problem. b)If the acid used in a. was nitric acid, HNO3, could the same buffer solution be made? Briefly explain. c) If the buffer solution prepared in a. also contained ~10–6M Ni2+ and ~10–6 M Pb2+ , could those metal ions be separated from each other by saturating the solution with H2S? Explain your answer by showing the necessary calculations.
a Calculate the pH of a solution that is 0.20 M HOCI and 0.88 M KOCI. Ka = 3.5x10-8 pH = 8.1 b In order for HOCI/KOCI buffer to have pH = pKa, would you add HCI or NaOH? pKa = 7.46 pH = 8.1 NaOH O HCI What quantity (moles) of HCI would you add to 1.0 L of the original buffer (0.20 M HOCI and 0.88 M KOCI) so that the resulting solution has pH = pKą? pka = 7.46 Quantity = mol Submit
A student wishes to make a buffer that has a pH of 4.65. The student has HNO2 and NaNO2. Nitrous Acid (HNO2) has a pKa of 3.40 The student makes 100.0 mL of a 0.100 M solution of HNO2. What mass (in grams) of NaNO2 should the student add to the solution to make a buffer that buffers at a pH of 4.25. (Hint: use the Henderson-Hasselbalch equation to find the molarity, then find the number of moles required to achieve that concentration in 100.0 mL of solution.)
4. How many moles of NH4C1 must be added to 2.0 L of 0.10 M NH3 to form a buffer whose pH is 9.00? (Kb =1.8x10-5. Assume that the addition of NH4C1 does not change the volume of the solution.)
Calculate the pH of a buffer solution prepared by dissolving 0,48 mole of sodium fluoride (NaF) and 1.0 mole of hydrofluoric acid (HF) in enough water to make 1.0 liter of solution. [K(HF) = 6,8 x 1o-j Your answer should have 2 sig figs
Which of the following statements is correct concerning the 3 buffer solutions given below? Choose one option only. Buffer A. prepared by mixing 1.32 mol NH3 and 3.26 mol NH4Cl into 2.20 L of solution. Ka (NH4+) = 5.6 x 10-10. Buffer B. prepared by mixing 1.18 mol HF and 2.48 mol NaF into 3.20 L of solution. Ka (HF) = 6.6 x 10-4. Buffer C. prepared by mixing 4.73 mol HOAc and 2.15 mol NaOAc into1.80 L of solution. Ka (HOAc) = 1.8 x 10-5. Options: a. The pH of Buffer A is between the pH values of Buffer B and Buffer C. b. Buffer C has the lowest pH. c. Buffer B has the lowest pH. d. Buffer A has the lowest pH. e. Buffer B and Buffer C have the same pH.
A buffer solution is made that is 0.409 M H2S and 0.409 M in NaHS. If Ka1 for H2S is 1.00x10^-7, what is the pH of the buffer solution? pH = Write the net ionic equation for the reaction that occurs when 0.087 mol NaOH is added to 1.00 L of the buffer solution. (Use the lowest possible coefficients. Omit states of matter.)
A 1.0-L buffer solution contains 0.100 mol acid, HA, and 0.100 mol base, NaA. The value of K, for the acid HA is 1.8x104. Ignoring the small volume change, what is the most likely pH of the solution if a 10.0 mL- sample of 1.00 M HCI is added to the original buffer? O 5.50 < pH < 5.74 O 3.51 < pH < 3.69 O 4.10 < pH < 4.22 O 1.20 < pH < 1.45