A chemistry graduate student is given 100. mL of a 1.80M trimethylamine ((CH3),N) solution. Trimethylamine is a weak base with K,=7.4 × 10". What mass of (CH,, NHC1 should the student dissolve in the (CH3),N solution to turn it into a buffer with pH =10.99? 3/3 You may assume that the volume of the solution doesn't change when the (CH;) NHC1 is dissolved in it. Be sure your answer has a unit symbol, and round it /3 to 2 significant digits.

A chemistry graduate student is given 100. mL of a 1.80M trimethylamine ((CH3),N) solution. Trimethylamine is a weak base with K,=7.4 × 10". What mass of (CH,, NHC1 should the student dissolve in the (CH3),N solution to turn it into a buffer with pH =10.99? 3/3 You may assume that the volume of the solution doesn't change when the (CH;) NHC1 is dissolved in it. Be sure your answer has a unit symbol, and round it /3 to 2 significant digits.

Chemistry: The Molecular Science

5th Edition

ISBN:9781285199047

Author:John W. Moore, Conrad L. Stanitski

Publisher:John W. Moore, Conrad L. Stanitski

Chapter15: Additional Aqueous Equilibria

Section: Chapter Questions

Problem 93QRT: When 40.00 mL of a weak monoprotic acid solution is titrated with 0.100-M NaOH, the equivalence...

See similar textbooks

Similar questions

You want to make a buffer with a pH of 10.00 from NH4+/NH3. (a) What must the [ NH4+ ]/[ NH3 ]ratio be? (b) How many moles of NH4Cl must be added to 465 mL of an aqueous solution of 1.24 M NH3 to give this pH? (c) How many milliliters of 0.236 M NH3 must be added to 2.08 g of NH4Cl to give this pH? (d) What volume of 0.499 M NH3 must be added to 395 mL, of 0.109 M NH4Cl to give this pH?
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.
Ammonia gas is bubbled into 275 mL of water to make an aqueous solution of ammonia. To prepare a buffer with a pH of 9.56, 15.0 g of NH4Cl are added. How many liters of NH3; at 25C and 0.981 atm should be used to prepare the buffer? Assume no volume changes and ignore the vapor pressure of water.
When 40.00 mL of a weak monoprotic acid solution is titrated with 0.100-M NaOH, the equivalence point is reached when 35.00 mL base has been added. After 20.00 mL NaOH solution has been added, the titration mixture has a pH of 5.75. Calculate the ionization constant of the acid.
Consider the titration of butyric acid (HBut) with sodium hydroxide. In an experiment, 50.00 mL of 0.350 M butyric acid is titrated with 0.225 M NaOH. Ka HBut=1.5105. (a) Write a balanced net ionic equation for the reaction that takes place during titration. (b) What are the species present at the equivalence point? (c) What volume of sodium hydroxide is required to reach the equivalence point? (d) What is the pH of the solution before any NaOH is added? (e) What is the pH of the solution halfway to the equivalence point? (f) What is the pH of the solution at the equivalence point?
A good buffer generally contains relatively equal concentrations of weak acid and conjugate base. If you wanted to buffer a solution at pH = 4.00 or pH = 10.00, how would you decide which weak acidconjugate base or weak baseconjugate acid pair to use? The second characteristic of a good buffer is good buffering capacity. What is the capacity of a buffer? How do the following buffers differ in capacity? How do they differ in pH? 0.01 M acetic acid/0.01 M sodium acetate 0.1 M acetic acid/0.1 M sodium acetate 1.0 M acetic acid/1.0 M sodium acetate
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).
What mass of NH4Cl must be added to 0.750 L of a 0.100-M solution of NH3 to give a buffer solution with a pH of 9.26? (Him: Assume a negligible change in volume as the solid is added.)
Marble is almost pure CaCO3. Acid rain has a devastating effect on marble statuary left outdoors. Assume that the reaction which occurs is CoCO3(s)+ H+(aq)Ca2+(aq)+HCO3(aq) Neglecting all other competing equilibria and using Tables 15.1 and 13.2, calculate (a) K for the reaction. (b) the molar solubility of CaCO3 in pure water. (c) the molar solubility of CaCO3 in acid rainwater with a pH of 4.00.
A chemistry graduate student is given 450. mL of a 0.70 M chlorous acid (HCIO2) solution. Chlorous acid is a weak acid with K=1.1 x 10^-2 . What mass of KClO, should the student dissolve in the HCIO, solution to turn it into a buffer with pH = 2.24? You may assume that the volume of the solution doesn't change when the KCIO, 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 250.mL of a 0.90M diethylamine ((C_2H_5)_2NH) solution. Diethylamine is a weak base with Kb = 1.3x10^−3. What mass of (C_2H_5)_2NH_2Cl should the student dissolve in the (C_2H_5)_2NH solution to turn it into a buffer with pH =11.57? You may assume that the volume of the solution doesn't change when the (C_2H_5)_2NH_2Cl 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 100.mL of a 0.40M trimethylamine ((CH3)3N) solution. Trimethylamine is a weak base with =Kb×7.410−4. What mass of (CH3)3NHCl should the student dissolve in the (CH3)3N solution to turn it into a buffer with pH =10.35? You may assume that the volume of the solution doesn't change when the (CH3)3NHCl is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.