Calculating the composition of a buffer of a given pH 4 A chemistry graduate student is given 125. mL of a 0.30M nitrous acid (HNO 2) solution. Nitrous acid is a weak acid with K = 4.5 × 10 NaNO2 should the student dissolve in the HNO₂ solution to turn it into a buffer with pH = 2.80? What mass of a You may assume that the volume of the solution doesn't change when the NaNO 2 is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits. ☐ ☐ x10 ☑ ? 18 Ar

Calculating the composition of a buffer of a given pH 4 A chemistry graduate student is given 125. mL of a 0.30M nitrous acid (HNO 2) solution. Nitrous acid is a weak acid with K = 4.5 × 10 NaNO2 should the student dissolve in the HNO₂ solution to turn it into a buffer with pH = 2.80? What mass of a You may assume that the volume of the solution doesn't change when the NaNO 2 is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits. ☐ ☐ x10 ☑ ? 18 Ar

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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A chemistry graduate student is given 250. mL of a 0.30M chloroacetic acid (HCH,CICO,) solution. Chloroacetic acid is a weak acid with K= 1.3 × 10 °. What mass of KCH,CICO, should the student dissolve in the HCH,CICO, solution to turn it into a buffer with pH = 2.80? You may assume that the volume of the solution doesn't change when the KCH,CICO, is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.
A chemistry graduate student is given 450. mL of a 0.40M acetic acid (HCH3CO2) solution. Acetic acid is a weak acid with K = 1.8 × 105. What mass of NaCH3CO2 should the student dissolve in the HCH3CO2 solution to turn it into a buffer with pH =5.04? You may assume that the volume of the solution doesn't change when the NaCH3CO2 is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits. 1 0.8 Explanation Check X G esc F2 80 F3 OOO 000 MacBook Air F4 F6 F7 2024 McGraw Hill LLC. All Rights Reserved. Terms of Use | Privacy Center | Accessibility 114 F8 F9 F10 F11 F12 000
A beaker with 1.0 x 10^2 mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 8.80 mL of a 0.360 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.740.
A chemistry graduate student is given 500. mL of a 1.80M hydrocyanic acid (HCN) solution. Hydrocyanic acid is a weak acid with K,= 4.9 x 10 – 10 What mass of KCN should the student dissolve in the HCN solution to turn it into a buffer with pH =9.70? 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. 国国回

+ pH Changes in Buffers When a solution contains a weak acid and its conjugate base or a weak base and its conjugate acid, it will be a buffer solution. Buffers resist change in pH following the addition of acid or base. A buffer solution prepared from a weak acid (HA) and its conjugate base (A) is represented as HA (aq) → H¹ (aq) + A (aq) The buffer will follow Le Châtelier's principle. If acid is added, the reaction shifts to consume the added H+, forming more HA. When base is added, the base will react with H+, reducing its concentration. The reaction then shifts to replace H+ through the dissociation of HA into H+ and A™. In both instances. [H] tends to remain constant. The pH of a buffer is calculated by using the Henderson-Hasselbalch equation: A] pH =pK₂ +log HA ▼ Part A pH = What is the pH of a buffer prepared by adding 0.607 mol of the weak acid HA to 0.507 mol of NaA in 2.00 L of solution? The dissociation constant K₁ of HA is 5.66 x 10-7 Express the pH numerically to three…
A chemistry graduate student is given 500.mL of a 0.80M chloroacetic acid (HCH2ClCO2) solution. Chloroacetic acid is a weak acid with Ka = 1.3x10^−3. What mass of NaCH2ClCO2 should the student dissolve in the HCH2ClCO2 solution to turn it into a buffer with pH = 3.08 ?You may assume that the volume of the solution doesn't change when the NaCH2ClCO2 is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.
If you wanted to create a buffer with a pH = 3.2, what substances would you choose to make the buffer? Weak Acid K, pK, HCIO, 7.2 x 10-3 1.94 HNO, CH,COOH H,CO, 4.0 x 10-4 3.39 1.8 x 10-5 4.75 6.3 x 10-8 6,35 HBRO 2.8 x 10-9 8.55 HCO, 4.0 x 10-13 10.33 HNO, and NO, CH;COOH only HNO, only HCO; and CO,2 HBГО and BrO HCIO, and CIO, CH3COOH and CH;COO
We have to make a borate buffer with pH = 8.8 where the boric acid pKa = 9.00. If we start with a 1 liter of 0.1 M boric acid solution, what mass of hydroxide ions should be added to get the desired pH? Boric acid has the molecular formula B (OH) 3 and the borate ion B (OH)
A buffer is made using 100.0 mL of 0.100 M CH3CH2COOH (propanoic acid) and 100.0 mL of 0.100 M NaCH3CH2COO (sodium propanoate). 10.0 mL of 0.100 M HCl is added to the buffer. What is the solution pH after the HCl is added?For CH3CH2COOH K = 1.3 x 10^-5
A chemistry graduate student is given 450. mL of a 1.70M hydrocyanic acid (HCN) solution. Hydrocyanic acid is a weak acid with K,= 4.9 × 10 ". What mass of KCN should the student dissolve in the HCN solution to turn it into a buffer with pH = 8.97? 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.
An aqueous solution contains 0.29 M ammonia. One liter of this solution could be converted into a buffer by the addition of: (Assume that the volume remains constant as each substance is added.) 0.15 mol Ba(OH)2 O 0.30 mol NH4Br 0.30 mol HNO3 O 0.29 mol BaBr2 0.15 mol HNO3
A chemistry graduate student is given 100. mL of a 0.90M 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 = 8.97? 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.