It's important to note for 7:56: having the same melting point is not a true confirmation that your two substances are identical. There is a method of determining of so-called "mixed melting point temperature". Having two substances with the same melting point you mix two small samples mechanically, with a spatula on a glass plate, to make 1:1 solid mixture, rubbing the mixture very carefully. And then you measure the melting point temperature of this fine mixture. If both substances are exactly same (except for optical isomers) then you will have same melting point or intermediate, if the two samples have slightly different M.P. But if the two substances in question are different and the same melting point is just a concidence, then you will see depression of the melting point and mixter will melt at much lower temperature. I successfully applied this ancient method in Moscow State University lab, because of lack of modern analytical equipment in the organic synthesis lab in russia.
Nice job. Often commercial activated carbon is not activated at all. Another procedure I suggest is in DMSO. Generate naphtolate ion by dissolvin it in DMSO along with potassium carbonate at 40 C, stirring for few hours. Then quickly add methyl iodide in 1.5 equivalent and stopper. Leave at least 24 h, but even more can be required. After, just pour in water, filter and proceed as usual.
