how can you separate pure benzoic acid from a mixture of benzoic acid and sand?

Answer 1

Is this an introductory course; how complicated can it get?
I wuld think you could add enough NaOH solution (weak) to neutralize the acid and that makes it soluble. Then you can filter the sand and dump it. Back to the aqueous solution, add HCl to bring the benzoic acid back out of solution, extract with ether, separate with a sep funnel, evaporate the ether, and recover the benzoic acid.