posted by Chad on .
What mass of benzoic acid can be made from a reaction where 4.87g benzyl alcohol is combined with 300mL of bleach? The reaction is conducted in water and dichloromethane. Describe a method of separating the benzoic acid from the sodium chloride byproduct after the reaction is complete.
Write the equation and balance it.
Convert 4.87 benzyl alcohol to moles. moles = grams/molar mass.
Using the coefficients in the balanced equation (I think it is 1:1 but you can tell from the balanced equation you wrote), convert moles benzyl alcohol to moles of the product, benzoic acid.
Now convert moles benzoic acid to grams benzoic acid. grams = moles x molar mass.
To separate the product, look at the solubilities of benzyl alcohol and benzoic acid in water and in dichloromethane.
If you treat the finished solution with NaHCO3, that will convert the acid to the sodium salt which will be soluble in water. You can then pour into a sep funnel and separate the organic phase from the water phase. I would wash two or three times to make sure I obtained all of the product. Then the aq phase can be acidified which will return the sodium benzoate to benzoic acid and extract with an organic phase, wash, dry, and evaporate the solvent.
Thank you Chad for asking this question and thank you Br. Bob for answering it!