Benzoic Acid Answers
How do you draw the mechanism (with curly arrows) for the reaction of methanol and benzoic acid?
Q. (Acid catalysed with H2SO4 to form methyl benzoate and H2O) Also, are the ratios of methanol to ester and Benzoic acid to ester both 1:1? Thanks I have a basic idea I just wasn't sure about exact details. Just saying what attacks what atom etc would help. I tried both my organic chemistry books and they don't show mechanisms:-s. Thanks for any help though.
Asked by curious fox - Mon Feb 9 15:24:56 2009 - Chemistry - 3 Answers - Comments
A. Not possible to draw them in text, other than to describe in words. The overall equation is C6H5COOH + CH3OH ---> C6H5COOCH3 + H2O First step is protonation of the carbonyl O of benzoic acid, so draw arrow from that O atom to an H+, and another arrow from the C=O bond to the carbonyl O atom. This will give you a structure that has two -OH groups on the C atom, and don't forget to place the positive charge there as well. Second step is for the lone pair of electrons on the O atom of CH3OH to bond to the positively charged C atom. The intermediate structure has two OH groups and the OHCH3 group bonded to the C atom now, and the positive charge has moved to the methanol O. To show this you draw the curly arrow from the O lone pair to the C+ [cont.]
Answered by rmjrenneboog - Mon Feb 9 15:39:40 2009
Q. (Acid catalysed with H2SO4 to form methyl benzoate and H2O) Also, are the ratios of methanol to ester and Benzoic acid to ester both 1:1? Thanks I have a basic idea I just wasn't sure about exact details. Just saying what attacks what atom etc would help. I tried both my organic chemistry books and they don't show mechanisms:-s. Thanks for any help though.
Asked by curious fox - Mon Feb 9 15:24:56 2009 - Chemistry - 3 Answers - Comments
A. Not possible to draw them in text, other than to describe in words. The overall equation is C6H5COOH + CH3OH ---> C6H5COOCH3 + H2O First step is protonation of the carbonyl O of benzoic acid, so draw arrow from that O atom to an H+, and another arrow from the C=O bond to the carbonyl O atom. This will give you a structure that has two -OH groups on the C atom, and don't forget to place the positive charge there as well. Second step is for the lone pair of electrons on the O atom of CH3OH to bond to the positively charged C atom. The intermediate structure has two OH groups and the OHCH3 group bonded to the C atom now, and the positive charge has moved to the methanol O. To show this you draw the curly arrow from the O lone pair to the C+ [cont.]
Answered by rmjrenneboog - Mon Feb 9 15:39:40 2009
What occurs when potassium permanganate is added to Benzoic acid?
Q. Potassium permanganate is added to benzoic acid in a test tube and is heated in a water bath. Is there a chemical reaction that occurs? Is permanganate reduced? According to other sources, there is no reaction that occurs. However, the solution turned turbid brown. If there was no reaction, shouldn't the solution remain purple (from the KMn O4)? How does it differ to the chemical reaction that occurs between potassium permanganate and formic acid?
Asked by SiriasBlack - Thu Aug 14 02:51:14 2008 - Chemistry - 1 Answers - Comments
A. IF there is a change in color... it is most probable that there was a chemical reaction... Im not so sure if this explains it correctly... anyway... 1. Benzoic Acid is a benzene ring (C6H6) with carboxylic acid (-COOH); in this case the -OH will be most likely to be attacked by electrophiles 2. Potassium Permanganate is K+ and Mn O4-; 3. If we will apply the substitution reaction, K+ will react with -OH grp of COOH, forming KOH and -Mn O4 will replace the -OH. 4. The same type reaction will be true for any other acid...
Answered by jmlomongo - Thu Aug 14 04:22:42 2008
Q. Potassium permanganate is added to benzoic acid in a test tube and is heated in a water bath. Is there a chemical reaction that occurs? Is permanganate reduced? According to other sources, there is no reaction that occurs. However, the solution turned turbid brown. If there was no reaction, shouldn't the solution remain purple (from the KMn O4)? How does it differ to the chemical reaction that occurs between potassium permanganate and formic acid?
Asked by SiriasBlack - Thu Aug 14 02:51:14 2008 - Chemistry - 1 Answers - Comments
A. IF there is a change in color... it is most probable that there was a chemical reaction... Im not so sure if this explains it correctly... anyway... 1. Benzoic Acid is a benzene ring (C6H6) with carboxylic acid (-COOH); in this case the -OH will be most likely to be attacked by electrophiles 2. Potassium Permanganate is K+ and Mn O4-; 3. If we will apply the substitution reaction, K+ will react with -OH grp of COOH, forming KOH and -Mn O4 will replace the -OH. 4. The same type reaction will be true for any other acid...
Answered by jmlomongo - Thu Aug 14 04:22:42 2008
What is the ratio of the concentration of benzoic acid to the concentration of benzoate ion in food?
Q. Sodium benzoate (Na C7H5O2) is used as a food preservative. The Ka of benzoic acid is 6.46 x 10^ -5M. What is the ratio of the concentration of benzoic acid to the concentration of benzoate ion in a food with p H=3.00?
Asked by BARBIEGURLxo - Fri Apr 15 16:38:52 2011 - Chemistry - 1 Answers - Comments
A. Are you OK with using the Henderson-Hasselbalch equation? If so, first calculate p Ka for benzoic acid: p Ka = - log Ka The H-H equation is: p H = p Ka + log [base]/[acid] In this problem, you are asked to calculate the ratio of acid to benzoate. When you solve the H-H equation for the log term ratio, you will need to take 1/___. Message me if this doesn't make sense...I'll try again tomorrow.
Answered by hcbiochem - Fri Apr 15 23:37:37 2011
Q. Sodium benzoate (Na C7H5O2) is used as a food preservative. The Ka of benzoic acid is 6.46 x 10^ -5M. What is the ratio of the concentration of benzoic acid to the concentration of benzoate ion in a food with p H=3.00?
Asked by BARBIEGURLxo - Fri Apr 15 16:38:52 2011 - Chemistry - 1 Answers - Comments
A. Are you OK with using the Henderson-Hasselbalch equation? If so, first calculate p Ka for benzoic acid: p Ka = - log Ka The H-H equation is: p H = p Ka + log [base]/[acid] In this problem, you are asked to calculate the ratio of acid to benzoate. When you solve the H-H equation for the log term ratio, you will need to take 1/___. Message me if this doesn't make sense...I'll try again tomorrow.
Answered by hcbiochem - Fri Apr 15 23:37:37 2011
What happens when you mix benzoic acid, sand, sodium carbonate and sulfurous acid in a nickel container?
Q. What reactions are occuring and what would be produced if you had a mixture of sand, benzoic acid and sodium carbonate held in a nickel container and added sulfurous acid? Would heat effect the reaction?
Asked by Jennifer C - Tue Apr 8 06:03:01 2008 - Chemistry - 2 Answers - Comments
A. Sand is relatively unreactive. I think you need HF to react with it, so H2SO3 and benzoic acid will not affect it. It may slow down reactions, however, by effectively causing dilution of the solids. Acid + carbonate -> salt + water + CO2, so both the benzoic acid and the sulfurous acid will react with the sodium carbonate, forming water, carbon dioxide and both sodium benzoate and sodium sulfite. The nickel should not be affected, since Na will displace Ni from its salts. Heating may speed up the reaction, decompose the sodium carbonate, or decompose the sulfurous acid into sulfur dioxide and water.
Answered by kumorifox - Tue Apr 8 06:56:38 2008
Q. What reactions are occuring and what would be produced if you had a mixture of sand, benzoic acid and sodium carbonate held in a nickel container and added sulfurous acid? Would heat effect the reaction?
Asked by Jennifer C - Tue Apr 8 06:03:01 2008 - Chemistry - 2 Answers - Comments
A. Sand is relatively unreactive. I think you need HF to react with it, so H2SO3 and benzoic acid will not affect it. It may slow down reactions, however, by effectively causing dilution of the solids. Acid + carbonate -> salt + water + CO2, so both the benzoic acid and the sulfurous acid will react with the sodium carbonate, forming water, carbon dioxide and both sodium benzoate and sodium sulfite. The nickel should not be affected, since Na will displace Ni from its salts. Heating may speed up the reaction, decompose the sodium carbonate, or decompose the sulfurous acid into sulfur dioxide and water.
Answered by kumorifox - Tue Apr 8 06:56:38 2008
What tests can you perform to determine between Benzoic Acid and Salicylic Acid?
Q. I am trying to find a test I can do to prove whether it is a Benzoic or Salicylic Acid.
Asked by Pointe Dancer Kid - Sun Apr 17 22:12:16 2011 - Chemistry - 1 Answers - Comments
Q. I am trying to find a test I can do to prove whether it is a Benzoic or Salicylic Acid.
Asked by Pointe Dancer Kid - Sun Apr 17 22:12:16 2011 - Chemistry - 1 Answers - Comments
Why is benzoic acid used as a standard compound for bomb calorimetry?
Q. I know a reaction used in a bomb calorimeter has to be clean, fast, and complete to find the heat capacity. However, I can't think of specific properties that make benzoic acid special. It's very stable by itself, but I can't think otherwise. Will you please help me? Thank you so much!!
Asked by Sp - Mon Sep 15 11:48:32 2008 - Chemistry - 2 Answers - Comments
A. You gave two reasons: complete combustion and stability. It's also available in very high purity and has a decent formula weight (122) to minimize weighing errors.
Answered by HPV - Mon Sep 15 11:58:12 2008
Q. I know a reaction used in a bomb calorimeter has to be clean, fast, and complete to find the heat capacity. However, I can't think of specific properties that make benzoic acid special. It's very stable by itself, but I can't think otherwise. Will you please help me? Thank you so much!!
Asked by Sp - Mon Sep 15 11:48:32 2008 - Chemistry - 2 Answers - Comments
A. You gave two reasons: complete combustion and stability. It's also available in very high purity and has a decent formula weight (122) to minimize weighing errors.
Answered by HPV - Mon Sep 15 11:58:12 2008
why does benzoic acid precipitate out when the aqueous layer is acidified with hydrochloric acid?
Q. This is about the extraction of acid-base. In this experiment, i have separated a mixture of benzoic acid and a neutral compound (triphenylmethanol) into its components by extraction. Then, why does benzoic acid precipitate out when the aqueous layer is acidified with hydrochloric acid?
Asked by aina najwa - Mon Jan 21 02:22:31 2008 - Chemistry - 1 Answers - Comments
A. I am not exactly sure but i will give my input. I know that often times organic molecules tend to form diffrent compounds due to the PH of the solution they are contained in. such as caffein. Methylene chloride mixed in with soda will not extract caffein from soda when simply mixed. The PH of the solution must be neutral for the caffein to jump from the soda to the solvent. This may be the same concept at work except for the fact that acedifying the your solution made the solution favor the benzoic acid molecule instead of sending its "Acid forming" hydrogen Ion to the alcohol it is dissolve in. Then again I am merely a 17 year old chemistry nut, who is up way past their bed time, have fun answering lazy peoples questions.
Answered by daniel a - Mon Jan 21 02:43:32 2008
Q. This is about the extraction of acid-base. In this experiment, i have separated a mixture of benzoic acid and a neutral compound (triphenylmethanol) into its components by extraction. Then, why does benzoic acid precipitate out when the aqueous layer is acidified with hydrochloric acid?
Asked by aina najwa - Mon Jan 21 02:22:31 2008 - Chemistry - 1 Answers - Comments
A. I am not exactly sure but i will give my input. I know that often times organic molecules tend to form diffrent compounds due to the PH of the solution they are contained in. such as caffein. Methylene chloride mixed in with soda will not extract caffein from soda when simply mixed. The PH of the solution must be neutral for the caffein to jump from the soda to the solvent. This may be the same concept at work except for the fact that acedifying the your solution made the solution favor the benzoic acid molecule instead of sending its "Acid forming" hydrogen Ion to the alcohol it is dissolve in. Then again I am merely a 17 year old chemistry nut, who is up way past their bed time, have fun answering lazy peoples questions.
Answered by daniel a - Mon Jan 21 02:43:32 2008
How do I find the volume of boiling water needed to dissolve 1g of benzoic acid?
Q. Also, if benzoic acid is wet, how would this affect it's melting point??
Asked by - Mon Sep 13 11:58:38 2010 - Chemistry - 1 Answers - Comments
A. "The solubility of benzoic acid in water is 6.80 g per 100 m L at 100 deg C" take the grams of benzoic acid that you have & use the ratio (100 ml / 6.8 grams benz) = the minimum amount of water if benzoic acid is wet, how would this affect it's melting point... it will begin to melt at a lower temp than benzoic acid's real melting point, & colntinue to melt over a range of temps where as pure & dry would have a sharp melting point @ 122.4 deg C
Answered by Steve O - Mon Sep 13 13:07:20 2010
Q. Also, if benzoic acid is wet, how would this affect it's melting point??
Asked by - Mon Sep 13 11:58:38 2010 - Chemistry - 1 Answers - Comments
A. "The solubility of benzoic acid in water is 6.80 g per 100 m L at 100 deg C" take the grams of benzoic acid that you have & use the ratio (100 ml / 6.8 grams benz) = the minimum amount of water if benzoic acid is wet, how would this affect it's melting point... it will begin to melt at a lower temp than benzoic acid's real melting point, & colntinue to melt over a range of temps where as pure & dry would have a sharp melting point @ 122.4 deg C
Answered by Steve O - Mon Sep 13 13:07:20 2010
What is the water solubility of benzoic acid?
Q. Problem: At 25deg C, a saturated solution of benzoic acid (C6H5CO2H; Ka = 6.4 multiplied by 10-5) has a p H of 2.80. Calculate the water solubility of benzoic acid in moles per liter and grams per 100. milliliters.
Asked by Peter Parker - Tue Jun 9 17:12:58 2009 - Chemistry - 1 Answers - Comments
A. Benzoic acid dissociates according to: C6H5COOH C6H5COO + H with Ka = [C6H5COO ] [H ] / [C6H5COOH] Ignoring the small contribution of self ionization of water, all H is formed due to dissociation of benzoic acid. Therefore the concentration of H and benzoate ions are the same: [C6H5COO ] = [H ] = 10^-p H = 10^(-2.8) = 1.585x10 3mol/L The concentration of undissociated benzoic acid equals total amount dissolved minus amount dissociated [C6H5COOH] = [C6H5COOH]0 - [C6H5COO ] = [C6H5COOH]0 - [H ] Hence: Ka = [H ]2 / ([C6H5COOH]0 - [H ]) So the total amount dissolved (= maximum soluble amount) is [C6H5COOH]0 = [H ]2/Ka + [H ] = ([H ]/Ka - 1) [H ] = (1.585x10 3)2/1.585x10 5 + 1.585x10 3) mol/L = (1.585x10 3)2/1.585x10 5 + 1.585x10 3) mol/L = 0.04 [cont.]
Answered by schmiso - Wed Jun 10 17:03:52 2009
Q. Problem: At 25deg C, a saturated solution of benzoic acid (C6H5CO2H; Ka = 6.4 multiplied by 10-5) has a p H of 2.80. Calculate the water solubility of benzoic acid in moles per liter and grams per 100. milliliters.
Asked by Peter Parker - Tue Jun 9 17:12:58 2009 - Chemistry - 1 Answers - Comments
A. Benzoic acid dissociates according to: C6H5COOH C6H5COO + H with Ka = [C6H5COO ] [H ] / [C6H5COOH] Ignoring the small contribution of self ionization of water, all H is formed due to dissociation of benzoic acid. Therefore the concentration of H and benzoate ions are the same: [C6H5COO ] = [H ] = 10^-p H = 10^(-2.8) = 1.585x10 3mol/L The concentration of undissociated benzoic acid equals total amount dissolved minus amount dissociated [C6H5COOH] = [C6H5COOH]0 - [C6H5COO ] = [C6H5COOH]0 - [H ] Hence: Ka = [H ]2 / ([C6H5COOH]0 - [H ]) So the total amount dissolved (= maximum soluble amount) is [C6H5COOH]0 = [H ]2/Ka + [H ] = ([H ]/Ka - 1) [H ] = (1.585x10 3)2/1.585x10 5 + 1.585x10 3) mol/L = (1.585x10 3)2/1.585x10 5 + 1.585x10 3) mol/L = 0.04 [cont.]
Answered by schmiso - Wed Jun 10 17:03:52 2009
How to determine the molar concentration of the benzoic acid?
Q. The p H in a solution of benzoic acid(HC7H5O2) is 2.355. I am guessing an ICE table will be needed but i have no clue what to do. any help would be appreciated
Asked by - Thu Jan 6 21:15:05 2011 - Chemistry - 1 Answers - Comments
A. Ka for benzoic acid is 6.5 x 10^-5 [H+]=10^- 2.355 = 0.004416 M C6H5COOH C6H5COO- + H+ at equilibrium [H+]= [C6H5COO-] = 0.004416 M 6.5 x 10^-5 = [H+][C6H5COO-]/ [C6H5COOH] = ( 0.004416)(0.004416) / [C6H5COOH] = 0.000195 / [C6H5COOH] [C6H5COOH] = 0.300 M
Answered by Dr.A - Fri Jan 7 06:16:56 2011
Q. The p H in a solution of benzoic acid(HC7H5O2) is 2.355. I am guessing an ICE table will be needed but i have no clue what to do. any help would be appreciated
Asked by - Thu Jan 6 21:15:05 2011 - Chemistry - 1 Answers - Comments
A. Ka for benzoic acid is 6.5 x 10^-5 [H+]=10^- 2.355 = 0.004416 M C6H5COOH C6H5COO- + H+ at equilibrium [H+]= [C6H5COO-] = 0.004416 M 6.5 x 10^-5 = [H+][C6H5COO-]/ [C6H5COOH] = ( 0.004416)(0.004416) / [C6H5COOH] = 0.000195 / [C6H5COOH] [C6H5COOH] = 0.300 M
Answered by Dr.A - Fri Jan 7 06:16:56 2011
How many grams benzoic acid should be added to change the buffer p H to 3.77?
Q. You prepare a buffer solution by dissolving 2.26 g each of benzoic acid, HC7H5O2, and sodium benzoate, Na C7H5O2, in 500.0 m L of water. Initial Buffer p H= 4.20 (b) how much benzoic acid (in grams), would you add to the 500.0 m L of buffer to change its p H to 3.77? thanks in advance!
Asked by J5krunner - Wed Mar 30 21:30:08 2011 - Chemistry - 1 Answers - Comments
A. p H = p Ka + log([A-]/[HA]) This is all you need, and of course a basic understanding for chemistry 1. Use initial values to calculate p Ka 2. Use the found p Ka and given p H value of 3.77 to find concentration [HA] keep in mind concentration changes as more liquid is added, this is a common mistake
Answered by - Sat Apr 2 20:12:48 2011
Q. You prepare a buffer solution by dissolving 2.26 g each of benzoic acid, HC7H5O2, and sodium benzoate, Na C7H5O2, in 500.0 m L of water. Initial Buffer p H= 4.20 (b) how much benzoic acid (in grams), would you add to the 500.0 m L of buffer to change its p H to 3.77? thanks in advance!
Asked by J5krunner - Wed Mar 30 21:30:08 2011 - Chemistry - 1 Answers - Comments
A. p H = p Ka + log([A-]/[HA]) This is all you need, and of course a basic understanding for chemistry 1. Use initial values to calculate p Ka 2. Use the found p Ka and given p H value of 3.77 to find concentration [HA] keep in mind concentration changes as more liquid is added, this is a common mistake
Answered by - Sat Apr 2 20:12:48 2011
Amount of Benzoic Acid in Rockstar Energy Drink ?
Q. Anybody knows the amount of benzoic acid they put in rockstar energy drink ? It's for an experiment I'm doing in class. If you look at the ingredient for the Juiced one, Benzoic Acid should be in there.
Asked by confusing - Thu Dec 11 15:08:34 2008 - Chemistry - 2 Answers - Comments
A. For a list of ingredients see But it gives no value for benzoic acid. I would suggest a low value mg per 100 ml
Answered by aaj - Thu Dec 11 15:26:49 2008
Q. Anybody knows the amount of benzoic acid they put in rockstar energy drink ? It's for an experiment I'm doing in class. If you look at the ingredient for the Juiced one, Benzoic Acid should be in there.
Asked by confusing - Thu Dec 11 15:08:34 2008 - Chemistry - 2 Answers - Comments
A. For a list of ingredients see But it gives no value for benzoic acid. I would suggest a low value mg per 100 ml
Answered by aaj - Thu Dec 11 15:26:49 2008
How do you make benzoic acid from sodium benzoate?
Q. I think its sodium benzoate + hydronium --> benzoic acid + water but im not sure. Thanks!
Asked by Jamie_McFadden06 - Thu Jan 21 18:46:42 2010 - Chemistry - 1 Answers - Comments
A. yes
Answered by Steve O - Thu Jan 21 19:57:09 2010
Q. I think its sodium benzoate + hydronium --> benzoic acid + water but im not sure. Thanks!
Asked by Jamie_McFadden06 - Thu Jan 21 18:46:42 2010 - Chemistry - 1 Answers - Comments
A. yes
Answered by Steve O - Thu Jan 21 19:57:09 2010
What is the chemical equation for the ionization of benzoic acid?
Q. I'm working on acid/base chemistry...I'm stuck on this one...it asks to write the chemical equation, equilibrium constant expression and the value of the equilibrium constant for benzoic acid...help!? and guidance would be appreciated! Thanks!
Asked by Big T - Sat Mar 7 19:17:18 2009 - Chemistry - 1 Answers - Comments
A. Benzoic acid is an organic (carbon based) acid that can dissociate (lose its acidic proton) in water. Here is the equation... C6H5COOH --> C6H5COO(-) + H(+) The equilibrium constant for this dissociation is 6.3 X 10-5... Does this help? ;-)
Answered by - Sat Mar 7 20:34:18 2009
Q. I'm working on acid/base chemistry...I'm stuck on this one...it asks to write the chemical equation, equilibrium constant expression and the value of the equilibrium constant for benzoic acid...help!? and guidance would be appreciated! Thanks!
Asked by Big T - Sat Mar 7 19:17:18 2009 - Chemistry - 1 Answers - Comments
A. Benzoic acid is an organic (carbon based) acid that can dissociate (lose its acidic proton) in water. Here is the equation... C6H5COOH --> C6H5COO(-) + H(+) The equilibrium constant for this dissociation is 6.3 X 10-5... Does this help? ;-)
Answered by - Sat Mar 7 20:34:18 2009
What could the impurities in benzoic acid be?
Q. I did a recrystalisation of benzoic acid and one question is "what can the impurities be"? can't it be anything though?
Asked by A-level Dude - Tue Oct 28 06:23:35 2008 - Chemistry - 1 Answers - Comments
A. benzoic acid contains the impurities phthalic acid and benzylbenzoate. when you cool the benzoic acid crystal come out of solution as its solubility in the solvent decreases. The impurities will remain in solution and can be filtered off.
Answered by HaSsAsIn ..SmOoTh CrImiNaL - Tue Oct 28 11:30:19 2008
Q. I did a recrystalisation of benzoic acid and one question is "what can the impurities be"? can't it be anything though?
Asked by A-level Dude - Tue Oct 28 06:23:35 2008 - Chemistry - 1 Answers - Comments
A. benzoic acid contains the impurities phthalic acid and benzylbenzoate. when you cool the benzoic acid crystal come out of solution as its solubility in the solvent decreases. The impurities will remain in solution and can be filtered off.
Answered by HaSsAsIn ..SmOoTh CrImiNaL - Tue Oct 28 11:30:19 2008
How do you calculate the p Ka of an acid which is 50 times stronger than benzoic acid (p Ka 4.2)?
Q. How do you calculate the p Ka of an acid which is 50 times stronger than benzoic acid (p Ka 4.2) Please show working out Thanks I got 2.5 is that correct?
Asked by Georgeboy93 - Sun Aug 29 08:43:11 2010 - Chemistry - 1 Answers - Comments
A. Convert p Ka of benzoic acid to its Ka multiply by 50 to get Ka of other acid Convert Ka of other acid to its p Ka
Answered by ChemTeam - Sun Aug 29 09:37:19 2010
Q. How do you calculate the p Ka of an acid which is 50 times stronger than benzoic acid (p Ka 4.2) Please show working out Thanks I got 2.5 is that correct?
Asked by Georgeboy93 - Sun Aug 29 08:43:11 2010 - Chemistry - 1 Answers - Comments
A. Convert p Ka of benzoic acid to its Ka multiply by 50 to get Ka of other acid Convert Ka of other acid to its p Ka
Answered by ChemTeam - Sun Aug 29 09:37:19 2010
How to make Benzoic Acid soluble and be able to find its weight?
Q. How would you be able to make Benzoic Acid soluble and be able to find its weight (grams).
Asked by - Tue Sep 21 20:16:07 2010 - Chemistry - 1 Answers - Comments
A. titrate it with a strong base such as sodium hydroxide to neutralise it. the salt (sodium benzoate) should be soluble. it may be difficult to detect this endpoint as the acid is insoluble, so it could be necessary to titrate the excess base with acid.
Answered by vorenhutz - Tue Sep 21 20:32:41 2010
Q. How would you be able to make Benzoic Acid soluble and be able to find its weight (grams).
Asked by - Tue Sep 21 20:16:07 2010 - Chemistry - 1 Answers - Comments
A. titrate it with a strong base such as sodium hydroxide to neutralise it. the salt (sodium benzoate) should be soluble. it may be difficult to detect this endpoint as the acid is insoluble, so it could be necessary to titrate the excess base with acid.
Answered by vorenhutz - Tue Sep 21 20:32:41 2010
What can you conclude about the state of the benzoic acid molecules?
Q. A solution of benzoic acid in benzene has a freezing point of 3.1o C and a boiling point of 82.6o C. The freezing point of pure benzene is 5.12o C and its boiling point is 80.1o C. What can you conclude about the state of the benzoic acid molecules at the two different sets of temperatures?
Asked by Goofing around for answers - Wed Sep 6 04:37:20 2006 - Chemistry - 1 Answers - Comments
A. There seems to be something wrong here a solute will lower the freezing point. Anyways fp depression and bp elevation are colligative properties - they depend on the number of solute molecules (size and mass are irrelevant). Benzoic acid is the classic example of a molecule that likes to dimerize in solution - probably more at lower temperatures. That is the point of the question - so work it out from there.
Answered by deflagrated - Wed Sep 6 07:27:45 2006
Q. A solution of benzoic acid in benzene has a freezing point of 3.1o C and a boiling point of 82.6o C. The freezing point of pure benzene is 5.12o C and its boiling point is 80.1o C. What can you conclude about the state of the benzoic acid molecules at the two different sets of temperatures?
Asked by Goofing around for answers - Wed Sep 6 04:37:20 2006 - Chemistry - 1 Answers - Comments
A. There seems to be something wrong here a solute will lower the freezing point. Anyways fp depression and bp elevation are colligative properties - they depend on the number of solute molecules (size and mass are irrelevant). Benzoic acid is the classic example of a molecule that likes to dimerize in solution - probably more at lower temperatures. That is the point of the question - so work it out from there.
Answered by deflagrated - Wed Sep 6 07:27:45 2006
How to separate para-substitued phenol and benzoic acid?
Q. I have a para-substitued phenol (the substitution is a ketone), and I need to separate it from benzoic acid. I thought I could use sodium bicarbonate, but my professor thought that the phenol would be acidic too. He suggested I should recrystallize it from hexane, which is what I'm trying now, but if that doesn't work, how should I separate the two compounds? Recrystallize benzoic acid from water and hope that the phenol stays in the mother liquor?
Asked by Robert Storm - Thu Jan 6 14:02:44 2011 - Chemistry - 1 Answers - Comments
A. The phenol is acidic, but not as strongly as the benzoic acid; therefore the benzoic acid will react first (preferentially). Sodium bicarbonate should work. You could add it slowly, with stirring, to avoid an excess - once all the benzoic acid has reacted, the only thing left to react is your phenol. Even without reaction, benzoic acid is pretty soluble in hot water and much less so in cold water. Add a small amount of hot water (just enough to cover the mixture?) and mix thoroughly, then drain off the water (still hot).
Answered by Mike S - Fri Jan 7 09:27:24 2011
Q. I have a para-substitued phenol (the substitution is a ketone), and I need to separate it from benzoic acid. I thought I could use sodium bicarbonate, but my professor thought that the phenol would be acidic too. He suggested I should recrystallize it from hexane, which is what I'm trying now, but if that doesn't work, how should I separate the two compounds? Recrystallize benzoic acid from water and hope that the phenol stays in the mother liquor?
Asked by Robert Storm - Thu Jan 6 14:02:44 2011 - Chemistry - 1 Answers - Comments
A. The phenol is acidic, but not as strongly as the benzoic acid; therefore the benzoic acid will react first (preferentially). Sodium bicarbonate should work. You could add it slowly, with stirring, to avoid an excess - once all the benzoic acid has reacted, the only thing left to react is your phenol. Even without reaction, benzoic acid is pretty soluble in hot water and much less so in cold water. Add a small amount of hot water (just enough to cover the mixture?) and mix thoroughly, then drain off the water (still hot).
Answered by Mike S - Fri Jan 7 09:27:24 2011
A student performs an esterification reaction between benzoic acid and methanol to give methyl benzoate and wa?
Q. A student performs an esterification reaction between benzoic acid and methanol to give methyl benzoate and water. The student starts with 1.07 moles of benzoic acid and 8.9 moles of methanol. At the end of the reaction 0.25 moles of benzoic acid are recovered. How much water is present at equilibrium? Express your answer in units of moles.
Asked by - Tue Oct 25 13:48:31 2011 - Chemistry - 1 Answers - Comments
A. Look at the balanced equation! One mole of ester and one mole of water is formed from each mole of benzoic acid reacted. So 1.07 - 0.25 moles benzoic acid react = 0.82 moles. So 0.82 moles of water are formed.
Answered by - Wed Oct 26 14:36:40 2011
Q. A student performs an esterification reaction between benzoic acid and methanol to give methyl benzoate and water. The student starts with 1.07 moles of benzoic acid and 8.9 moles of methanol. At the end of the reaction 0.25 moles of benzoic acid are recovered. How much water is present at equilibrium? Express your answer in units of moles.
Asked by - Tue Oct 25 13:48:31 2011 - Chemistry - 1 Answers - Comments
A. Look at the balanced equation! One mole of ester and one mole of water is formed from each mole of benzoic acid reacted. So 1.07 - 0.25 moles benzoic acid react = 0.82 moles. So 0.82 moles of water are formed.
Answered by - Wed Oct 26 14:36:40 2011
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