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A student was working on her yield determination of herrecrystallized p-aminoben

ID: 689973 • Letter: A

Question

A student was working on her yield determination of herrecrystallized p-aminobenzoic acid, when some naphthalene wasinadvertently spilt into her crystals. You happen along the scene,and offer the following advice to the distraught student:
a) Redissolve all the solid in dichloromethane, extractwith dilute aqueous acid, , re-isolate the organic compound byprecipitating the salt of the base with strong base, andrecrystallize your p- aminobenzoic acid again
b) Redissolve all the solid in dichloromethane,extract with dilute aqueous base, re-isolate the organic compoundby precipitating the salt of the acid with strong acid andrecrystallize p- aminobenzoic acid again.
c) Do either a or b.
d) Discard everything into the hazardous waste container.Nothing can be done.
Please help, wil rate lifesaver! A student was working on her yield determination of herrecrystallized p-aminobenzoic acid, when some naphthalene wasinadvertently spilt into her crystals. You happen along the scene,and offer the following advice to the distraught student:
a) Redissolve all the solid in dichloromethane, extractwith dilute aqueous acid, , re-isolate the organic compound byprecipitating the salt of the base with strong base, andrecrystallize your p- aminobenzoic acid again
b) Redissolve all the solid in dichloromethane,extract with dilute aqueous base, re-isolate the organic compoundby precipitating the salt of the acid with strong acid andrecrystallize p- aminobenzoic acid again.
c) Do either a or b.
d) Discard everything into the hazardous waste container.Nothing can be done.
Please help, wil rate lifesaver!

Explanation / Answer

A student was working on her yield determination of herrecrystallized p-aminobenzoic acid, when some naphthalene wasinadvertently spilt into her crystals. You happen along the scene,and offer the following advice to the distraught student: answer b) Redissolve all the solid in dichloromethane, extract withdilute aqueous base, re-isolate the organic compound byprecipitating the salt of the acid with strong acid andrecrystallize p- aminobenzoic acid again. here the recrystallized p-aminobenzoic acid, is extracted withdilute aquesous base so that reaction takes place and byprecipitation of the acid salt with other strong acidwe get finally p- aminobenzoic acid again.