The study of the verification of the acid recrystallized pcrico was carried through through the digital device of the fusing point aiming at to determine the pureness degree. It is important to point out that it had a reduction of impurities in crystals, not being able to affirm that the reached result was considered a pure substance. Word-key: Point of fusing. pcrico Pureza.cido ABSTRACT The study of verification of recrystallized picric acid was performed using digital melting point you determines the degree of purity. Importantly, there was reduction of impurities in the crystals and can not say that the result achieved was considered pure substance. (Not to be confused with LEGO Papert Professor!). Keywords: Point of fusing. Pureness.

Picric cid 1.INTRODUO the point of fusing of a crystalline solid is the temperature band in which the solid starts if to become liquid under the atmospheric pressure. If in a organic composition sample it will have presence of miscible or partially miscible impurities, the difference enters the first formation of the liquid and formation of the total fusing increases sufficiently, being that in the fusing point it goes to initiate with a temperature low. Already when the substance is pure a point of fusing with the lesser interval of 0,5C is had. Obs: A composition presents high degree of pureness when its point of fusing is clear-cut. Objective: Purificar and to evaluate the degree of pureness of the acid pcrico through comparisons of the point of fusing gotten with the one of literature. 2.PARTE EXPERIMENTAL USED MATERIALS REACTING USED – digital Device of fusing point.

– Acid recrystallized pcrico – Plated – Acid pcrico before the recrystallization – Cotton – Alcohol – Spatula With the aid of a spatula left small amount of the sample of acid recrystallized pcrico, placing enters two plated of previously clean glass with a humidified ball of cotton in alcohol. After that it was led to the digital device T): 18,1C Variation of the heating in the device of RECRYSTALLIZED 10C/min ACID PCRICO Temperature of fusing: 119,6C final Temperature of fusing: 122,3C Variation of the temperature of fusing ( T): 2,7C Variation of the heating in the device of 15C/min, when reaching 115C was diminished this variation for 5C/min.> 4.DISCUSSO In the practical one of recrystallization of the acid pcrico the same had reduction of impurities in comparison before the recrystallization, being detected through the reading of the device of fusing point. Exactly having reduction of impurities a pure substance was not considered, therefore so that it is pure it would have that to present a variation of inferior fusing of 0,5C and the band of 2,7 reached variation was of C. 5.CONCLUSO In accordance with the results gotten in comparison with what literature presents in relation to the point of fusing of the acid pcrico, can be affirmed that the acid one total was not purificado, and for this, it is necessary to repeat the process of purificao for some times.