Ochem Lab Report 6 - A nna Trujillo Ochem 1 Lab E xperiment...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Anna Trujillo Ochem 1 Lab Experiment 6 October 13, 2010 Recrystallization and Melting Points: Recrystallization of an Unknown Solid and Decolorization of Brown Sugar Abstract: The identities of two unknown solid compounds were identified by method of recrystallization and confirmed by melting point range measurements. Unknown compound S was found to have a percent crystal recovery weight of 70% and was identified as succinic acid, while unknown substance 9 had an 82% crystal recovery weight and identified as 4- acetylbiphenyl. The adsorption of brown sugar by activated charcoal noted a decolorization in the collected filtrate, removing a significant amount of molasses found in partially refined brown sugar. Experimental: Part I Recrystallization of an Unknown Divided into groups of four, each group was assigned 500 mg of an unknown solid. Assigned to unknown compound S, each member was assigned to approximately 100 mg of this unknown and then proceeded to test the solid’s solubility in the following solvents: 95% ethanol, reagent grade acetone, hexane, and water. Solubility of the unknown was also tested in diethyl ether at room temperature. Taking approximately ¼ of the 100 mg of the unknown, it was then poured into a small test tube and added only a few drops of the solvent being tested. The unknown did not dissolve in any of the tested solvents at room temperature including diethyl ether. A boiling stick was then added into the test tube and the solid now with the present solvent mixed in, was heated on a sand bath to determine the crystals’ solubility in hot solvent. Compound S dissolved in ethanol, acetone, and water when heated. The unknown heated in the hexane solvent reached a boiling point of 151 C and crystals remained intact, indicating that it was not soluble in hexane even when heated. Hexane was then set aside, since the unknown’s insolubility in hexane was determined. Unknown was not heated in diethyl ether. All solutions of the unknown that dissolved when heated, including ethanol, acetone, and water were then allowed to let cool at room temperature and left undisturbed for several minutes to observe if recrystallization occurred. No crystals were observed when unknown cooled at room temperature in ethanol or acetone. When cooled at room temperature in water, very few crystals were observed. Solutions were then cooled in an ice-water bath to determine if crystals could be recovered from the solution. No recrystallization was
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Anna Trujillo Ochem 1 Lab Experiment 6 October 13, 2010 observed in either ethanol or acetone, and very few crystals were observed in water. It was
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/16/2011 for the course OCHEM 112 taught by Professor Dr.patish during the Spring '11 term at University of California, Santa Cruz.

Page1 / 5

Ochem Lab Report 6 - A nna Trujillo Ochem 1 Lab E xperiment...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online