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I am suppose to calculate the theoretical amount (volume) of 3M sodium hydroxide needed to convert 1.5 g of benzoic acid to its salt.

Also calculate the volume of 12M HCl needed to convert the sodium benzoate back to benzoic acid.
how do I go about doing this?
Thanks

2 answers

It's a stoichiometry problem. Actually, two of them. I'll do the first and leave the second for you. By the way, the lasrt one I worked almost completely for you BECAUSE I wanted to print it out (with the solution) and put in a notebook I keep. I think benzoic acid is
C6H5COOH + NaOH ==> C6H5COONa + HOH

Convert 1.5 g benzoic acid to moles.
moles = grams/molar mass.
Using the coefficients in the balanced equation, convert moles benzoic acid to moles of NaOH.(It's 1:1)

Now convert moles NaOH to volume.
M = moles/L. You know moles and M, calculate L.

For the second part, you're going the other way BUT you already now how many moles benzoic acid you started with. The moles of the salt will be the same thing. You can go directly to the last step and convert 12 M HCl to volume needed.
I'm doing the same thing but I do not understand it fully. All of my general chemistry knowledge is gone.