Benzoic acid is a weak acid, which means that its dissociation is reversible.
C6H5COOH -----> C6H5COO- + H+
At pH 2, there are a lot of H+ ions in the solution. According to Le Chatelier's Principle, the equilibrium will shift to the left to favor the opposite reaction where Benzoic acid is produced, to reduce the amount of H+ in the solution. Therefore, an insignificant amount of benzoic acid will dissociate, while most of it remains in the molecular form.
Depending on its concentration.Examples:1.0 mol/L >> pH = 2.10.01 mol/L >> pH = 3.1
To dissolve benzoic acid, the aqueous system should be slightly acidic with a pH around 2-3. This can be achieved by adding a small amount of hydrochloric acid to water. Benzoic acid is sparingly soluble in pure water but dissolves more readily in an acidic solution due to the formation of benzoate ions.
One way to separate this mixture is through a process called liquid-liquid extraction. Aniline and benzoic acid are both water-soluble, while chloroform is not. By adding water to the mixture, the aniline and benzoic acid will dissolve in the water phase, leaving the chloroform to be separated out. The aniline and benzoic acid can then be recovered from the water phase by adjusting the pH of the solution.
Sodium benzoate is a salt derived from benzoic acid, which is weakly acidic. The pH of a solution containing sodium benzoate would depend on the concentration of the solution, but typically it would be acidic with a pH below 7.
pH = -log10(Ka) - log10([HA]/[A-])= 4.20 - log10([HA]/[A-])in which[HA] = 15.265(g) / 122.1(g.mol-1) / 500(mL) = 2.500*10-4 mol/mLand[A-] = 12.97(g) / 144.1(g.mol-1) / 500(mL) = 1.800*10-4 mol/mLSo pH = 4.20 - log10([2.5]/[1.8]) = 4.20 - log10(1.39) = 4.20 - 0.14 = 4.06
Depending on its concentration.Examples:1.0 mol/L >> pH = 2.10.01 mol/L >> pH = 3.1
When you're attempting to extract benzoic acid from other organic compounds, it is necessary to change its pH by adding a layer of an basic compound such as 1M NaOH so that the benzoic acid then can be separated from the organic layer within a separatory funnel. When in NaOH, the benzoic acid loses a proton and thus becomes its conjugate base (the benzoate ion). The benzoate ion is charged and thus become miscible in the aqueous layer. To extract benzoic acid (ie get it to precipitate out of solution), a strong acid such as HCl must be added to solution. After the extraction, lower the pH of the solution, and recrystalize (use ice after the recrystalization to get benzoic acid crystals to crash out).
To dissolve benzoic acid, the aqueous system should be slightly acidic with a pH around 2-3. This can be achieved by adding a small amount of hydrochloric acid to water. Benzoic acid is sparingly soluble in pure water but dissolves more readily in an acidic solution due to the formation of benzoate ions.
At the equivalence point, the moles of NaOH added will equal the moles of benzoic acid initially present in the sample. Since benzoic acid is a weak acid, it will partially dissociate in solution to produce benzoate ions and protons. At the equivalence point, all the benzoic acid has been converted to benzoate ions, resulting in a buffer solution of benzoate and its conjugate base. To calculate the pH at the equivalence point, you can use the Henderson-Hasselbalch equation, which considers the concentration of benzoate ions and benzoic acid to determine the pH of the solution.
One way to separate this mixture is through a process called liquid-liquid extraction. Aniline and benzoic acid are both water-soluble, while chloroform is not. By adding water to the mixture, the aniline and benzoic acid will dissolve in the water phase, leaving the chloroform to be separated out. The aniline and benzoic acid can then be recovered from the water phase by adjusting the pH of the solution.
To create a buffer with a pH of 4.30, you need to use the Henderson-Hasselbalch equation and the pKa of benzoic acid to calculate the ratio of benzoate ion to benzoic acid. From there, you can determine the moles of sodium benzoate needed and then convert it to grams. Make sure to consider the volume change when adding the sodium benzoate to the solution.
Sodium benzoate is a salt derived from benzoic acid, which is weakly acidic. The pH of a solution containing sodium benzoate would depend on the concentration of the solution, but typically it would be acidic with a pH below 7.
pH = -log10(Ka) - log10([HA]/[A-])= 4.20 - log10([HA]/[A-])in which[HA] = 15.265(g) / 122.1(g.mol-1) / 500(mL) = 2.500*10-4 mol/mLand[A-] = 12.97(g) / 144.1(g.mol-1) / 500(mL) = 1.800*10-4 mol/mLSo pH = 4.20 - log10([2.5]/[1.8]) = 4.20 - log10(1.39) = 4.20 - 0.14 = 4.06
Hydrochloric acid typically has a pH of 0 when in its concentrated form.
Adding an acid to a solution can cause the ph to decrease. Looking at things in the molecular level a good acid or something that will be able to decrease the ph will be anything that can easily donate an H+ ion to a solution. Strong acids are examples
you can easily prove this by testing nitric acid with pH paper...if the color matches to any of the pH levels form 0-7, it is an acid
You can separate benzoic acid from para-nitroaniline using liquid-liquid extraction by exploiting their different solubilities in different solvents. Benzoic acid is soluble in aqueous solutions, while para-nitroaniline is insoluble in water but soluble in organic solvents. By carefully selecting the appropriate solvents and adjusting pH levels, you can successfully separate the two compounds through multiple extraction steps.