crystallization word

crystallization word - Organic Chemistry Lab 223 -...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Organic Chemistry Lab 223 - Experiment 3 - Crystallization Monica Doyle Instructor: Eddie Date: 03/11/2010 Introduction: Recrystallization is a widely used technique to purify a solid mixture. The desired product is isolated from its impurities by differences in solubility. Insoluble impurities and colored impurites can be removed from hot solvent by activated carbon and filtration. Soluble impurities remain in the cold solvent after recrystallization. The desired product should be as soluble as possible in hot solvent and as insoluble as possible in cold solvent. The selection of solvent is, therefore, critical to a successful recrystallization. Description: The purpose of this report is to identify two unknowns. First using water as a solvent, and identifying unknown among three different possibilities, benzoic acid, sali- cylic acid and sorbic acid. And second using ethanol-water mixture as solvent, and identifying unknown among five different possibilities: p-nitroaniline, m-nitroaniline, naphtalene, cholesterol, p-bromacetanilide. The idendification could be done by melting point technique described on experiment 1 of this course. Percent recovery was found for each compound after weighting samples before crystallization process and after sample was filtered and air dried. Comments: 1.99g of compound C was used to perform part A of the experiment. It has an ap- pearence of a white powder, larger crystals. After recrystallization, a sample of 1.16g was recovered, giving a yield of 58%. Using this data as base for my results, it must e said that some of the sample was lost in the process of the experiment, or when cooling sample, trying to get as much out of it by cooling it in an ice bath, some of the sample
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/18/2010 for the course ORGO 222 taught by Professor Santoro during the Spring '10 term at Aarhus Universitet.

Page1 / 3

crystallization word - Organic Chemistry Lab 223 -...

This preview shows document pages 1 - 2. Sign up to view the full document.

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