Jump to content
APC Forum

what to do with benzoic acid?


FlaMtnBkr

Recommended Posts

I bought 10 lbs of benzoic acid somewhat spur of the moment thinking I would make copper benzoate. After doing some research I see it is not very easy to do using benzoic acid as a precursor.

 

So is there anything else I can use it for? I wonder if it will work as a fuel in whistle? It smells almost exactly like K or Na benzoate and it is a very strong odor. Not that smell means anything, just something I noticed.

 

Thanks!

Link to comment
Share on other sites

I have heard that barium benzoate and barium chlorate will make a nice colour though not a whistle. If I remember correctly, you can simply make barium benzoate from benzoic acid and barium carbonate.
Link to comment
Share on other sites

I bought 10 lbs of benzoic acid somewhat spur of the moment thinking I would make copper benzoate. After doing some research I see it is not very easy to do using benzoic acid as a precursor. So is there anything else I can use it for? I wonder if it will work as a fuel in whistle? It smells almost exactly like K or Na benzoate and it is a very strong odor. Not that smell means anything, just something I noticed.

Thanks!

 

Benzoic acid is more soluble in alcohol than water at room temperature (I believe) and an alcoholic solution of it would probably work better to make copper (II) benzoate than a water solution, if my guess is right. Either copper carbonate or copper hydroxide may work as the base of choice in the reaction. Good luck and let us know what you decide.

 

WSM B)

 

Edit: if you want to make potassium benzoate or sodium benzoate, try making a benzoic acid solution in alcohol (try denatured ethanol) and neutralize it with a hydroxide solution of sodium or potassium. If you balance the Moles of each reactant, it should work nicely. I recommend a vacuum filtration of the filtrate and dry the product over a water bath before powdering it.

Edited by WSM
Link to comment
Share on other sites

Ah chemistrywub.gif.

Where there is a will there is a way.2rolleyes.gif

 

Making your own chems is sometimes a necessity. Other times it is just easier to buy it. Sodium Benzoate and Potassium Benzoate are both readily available and quite cheap.

Link to comment
Share on other sites

Making your own chems is sometimes a necessity. Other times it is just easier to buy it. Sodium Benzoate and Potassium Benzoate are both readily available and quite cheap.

 

True, but not always available.

 

If you have benzoic acid and copper powder, a mixture of the two in the proper proportions can sometimes be used as a substitution for the copper benzoate, according to C-J White in Pyrotechnica (if I remember correctly).

 

WSM B)

Link to comment
Share on other sites

I've made Copper benzoate with Benzoic acid and 'Basic Copper carbonate' (I believe a carbonate/hydroxide complex?).

 

I forced the reaction by boiling it all together for hours (in water). It did take a while, and the benzoic acid acid was fairly hard to get stuff for me, so the Sodium benzoate/soluble Copper salt route was the one I usually use. However, if I had that much Benazoic acid, I might have done that. Avoiding the sodium wash is a bonus.

Link to comment
Share on other sites

I've made Copper benzoate with Benzoic acid and 'Basic Copper carbonate' (I believe a carbonate/hydroxide complex?).

I forced the reaction by boiling it all together for hours (in water). It did take a while, and the benzoic acid acid was fairly hard to get stuff for me, so the Sodium benzoate/soluble Copper salt route was the one I usually use. However, if I had that much Benazoic acid, I might have done that. Avoiding the sodium wash is a bonus.

 

I see where you've been with this. If I were to make copper benzoate by double displacement I would prefer to do it with copper sulfate (copper nitrate would be even better!) and potassium benzoate. There would be no sodium contamination and if copper nitrate were used instead the results would all be usable.

 

We don't always have the option but that would be a nicer way to go...

 

WSM B)

Link to comment
Share on other sites

Doing the reaction in alcohol with copper carbonate would be an interesting one actually. When you do it in water, you get a hydrate out. However, if you do the synthesis in the presence of alcohol you get an ethanol adduct out. Both will desolvate to the same compound, but the alcohol one may be a little quicker burning or something.

 

By the way, if you want to make the reaction happen quickly dissolve the copper carbonate in vinegar first. If you add a solution of benzoic acid in water or alcohol to the copper acetate solution, the product should crash right out. You may need to warm both the alcohol and water solutions to get enough into solution.

Link to comment
Share on other sites

i would be careful informing others you have benzoic acid, it can be used in the manufacture of benzoyl peroxide based compounds, I'm not sure about America but in NZ they are illegal
Link to comment
Share on other sites

it is an extremely common chemical, useful as a food preservative, found in medications, even used in chemistry demonstations for young kids...
Link to comment
Share on other sites

i would be careful informing others you have benzoic acid, it can be used in the manufacture of benzoyl peroxide based compounds, I'm not sure about America but in NZ they are illegal

 

Nice Wikki-foo there MMDC, it's not the compounds that are illegal, I am pretty sure you can buy acne cream down under.

 

Benzoyl peroxide (BPO) discussion needs to stay in the HE area IMHO.

 

-dag

Link to comment
Share on other sites

What does Benzylpiperazine have anything to do with benzoic acid or your first tangent of benzoyl peroxide? Trying to claim that benzoic acid is a legitimate precursor for BZP is a big stretch at the least.
Link to comment
Share on other sites

×
×
  • Create New...