During an experiment, a student mixed 14.5 mL of a 0.500 M sodium fluoride solution with 15.6 mL of a 0.750 M hydrofluoric acid solution. The measured pH was 3.24. Calculate the pKa   Calculate the pH of a solution prepared by mixing 20.5 mL of a 0.500 M sodium flouride solution with 32.5 mL of a 0.750 M hydrofluoric acid solution. Use the pKa calculated from question 1.

Which of the following aqueous solutions are good buffer systems?   0.13 M acetic acid + 0.20 M sodium acetate 0.20 M nitric acid + 0.25 M sodium nitrate 0.28 M ammonium nitrate + 0.36 M ammonia 0.13 M potassium hydroxide + 0.22 M potassium chloride 0.32 M nitrous acid + 0.30 M sodium nitrite

Which of the following aqueous solutions are good buffer systems?. 0.30 M nitric acid + 0.22 M sodium  nitrate 0.16 M sodium hydroxide + 0.21 M sodium  bromide 0.25 M ammonia + 0.32 M ammonium  nitrate 0.38 M barium perchlorate + 0.22 M barium bromide 0.20 M nitrous acid + 0.12 M sodium  nitrite

a) Determine the mass (in grams) of sodium formate that must be added to 1.00 L of 0.180 M formic acid to prepare a buffer with a pH = 3.50. Assume there is no change in volume upon addition of the sodium formate. b) Write the predominant chemical reaction that occurs when 0.050 mol of HClO4 is added to 1.00 L of the buffer prepared in part a and calculate the pH of the solution.

You need to prepare 100.0 mL of a pH 4.00 buffer solution using 0.100 M benzoic acid (pKa 4.20) and 0.240 M sodium benzoate. How many milliliters of each solution should be mixed to prepare this buffer? benzoic acid: mL sodium benzoate: mL

A solution containing 25.00 ml of 0.10 M acetic acid was made, determine the pH of this solution. Ka= 1.8 ×10−5

A 29.6 mL sample of 0.271 M dimethylamine, (CH3)2NH, is titrated with 0.237 M hydrobromic acid. After adding 12.9 mL of hydrobromic acid, the pH is Use the Tables link in the References for any equilibrium constants that are required.

+ 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…

An analytical chemist is titrating 198.6 mL of a 0.7200M solution of formic acid (H₂CO₂) with a 0.7700M solution of KOH. The p K of formic acid is 3.74. Calculate the pH of the acid solution after the chemist has added 209.6 mL of the KOH solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of KOH solution added. Round your answer to 2 decimal places.

Which of the following aqueous solutions are good buffer systems? 0.26 M ammonia + 0.36 M potassium hydroxide 0.18 M hypochlorous acid + 0.13 M sodium hypochlorite 0.18 M calcium hydroxide + 0.29 M calcium chloride 0.34 M potassium bromide + 0.25 M barium bromide 0.28 M perchloric acid + 0.19 M potassium perchlorate