A chemist prepared a buffer by mixing stock solutions of acetic acid and sodium acetate together to obtain concentrations of [acetic acid] = 0.10 M and [sodium acetate] = 0.15 M in the final solution.However, when they measured the pH of the prepared buffer solution, the pH turned out to be higher than expected according to their calculation. What should the chemist do to fix the pH of the buffer? Question 6AnswerAdd more acetic acidAdd a small amount of waterAdd a small amount of solid NaOHAdd more sodium acetateReduce the volume of the buffer solution by boiling off some solvent
Question
A chemist prepared a buffer by mixing stock solutions of acetic acid and sodium acetate together to obtain concentrations of [acetic acid] = 0.10 M and [sodium acetate] = 0.15 M in the final solution.However, when they measured the pH of the prepared buffer solution, the pH turned out to be higher than expected according to their calculation. What should the chemist do to fix the pH of the buffer? Question 6AnswerAdd more acetic acidAdd a small amount of waterAdd a small amount of solid NaOHAdd more sodium acetateReduce the volume of the buffer solution by boiling off some solvent
Solution
The chemist should add more acetic acid to the buffer solution. The pH of a buffer solution is determined by the ratio of the concentration of the weak acid (acetic acid in this case) to the concentration of its conjugate base (sodium acetate in this case). If the pH is too high, this means that the solution is too basic, which in turn means that there is too much of the conjugate base (sodium acetate) relative to the weak acid (acetic acid). By adding more acetic acid, the chemist can increase the concentration of the weak acid, thereby lowering the pH of the buffer solution.
Similar Questions
This question concerns part 1 of the lab. You mixed acetic acid and sodium acetate solutions together in the proportions calculated earlier. Although your target pH was 5.40, the actual pH of the buffer solution you created was 5.47, as measured by a pH meter.What is the % difference between the experimental pH and the target pH? Report your answer to at least one decimal place.The formula you need is as follows:
This question concerns part 1 of this lab.You need to make a buffer solution by mixing both a weak acid and its conjugate base in the right proportions to achieve the desired pH.Your desired target pH is 5.40. You have been provided with 5.00 mL of 0.100 M acetic acid solution.How many moles of sodium acetate do you need to add to this solution to obtain a buffer solution at the desired pH? The pKa of acetic acid is 4.74. Answer:
Calculate the pH of a buffer solution prepared by mixing 0.2 moles of acetic acid (CH₃COOH) and 0.2 moles of sodium acetate (CH₃COONa) in enough water to make a total volume of 1 liter. The pKa of acetic acid is 5.42.Select one:a.5.4b.5.8c.6.3d.4.5
What is the final pH of a buffer solution made by mixing 10 mL of 0.6% Acetic Acid (CH3COOH; MW = 60.05; pKa = 4.8) with 50 mL of a 1.36% Sodium Acetate (CH3COONa.3H2O; MW = 136.1) solution?pH = pka + log[salt]/[acid]4.1b.4.5c.5.15d.5.5e.9.8
This question concerns part 2 of the lab.Your target pH is still 5.40, and you are starting with 10.0 mL of 0.100 M sodium acetate solution. To create the buffer, you use a burette filled with 0.100 M HCl solution and dip a pH meter into the sodium acetate solution.You add HCl from the burette until the pH meter reads 5.40 exactly.How volume of HCl (in mL) should have been added from the burette at this point ? Please note in real life the actual volume needed may differ from the "ideal" calculated value. Report your answer to two decimal places.Answer:
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.