Experiment 1 1 20g10mL14g 143 mL is the minimum amount of ethanol needed to

Experiment 1 1 20g10ml14g 143 ml is the minimum

• Lab Report
• 6

This preview shows page 5 - 6 out of 6 pages.

calculate for the mass of methylene chloride in 38 drops. Experiment 1: 1. (2.0g*(10mL))/1.4g= 14.3 mL is the minimum amount of ethanol needed to recrystallize 2.0g sample of compound X (14.3mL* 0.21g)/10mL= 0.3g of compound X will remain dissolved in the cold solvent. 2. It is necessary to use only a minimal amount of hot solvent because excess of solvent will prevent recrystallization. The excess solvent will keep the compound partially dissolved, preventing crystallization. 3. If a preheated filter is not used during the gravity filtration step, the compound will start to recrystallize on the filter paper itself. This will hinder the separation of the pure compound from impurities. 4. Benzyl alcohol is not a good choice for recrystallization for fluorenol because the boiling point of Benzyl alcohol is 205 °C, which is more than the melting point of fluorenone. This will cause the liquid fluorenone to separate from the alcohol when the solution cools, preventing recrystallization, thus making it a poor choice of solvent. 5. A. Sand can be removed using the regular gravity filtration B. Colored organic contaminants can be removed using activated charcoal when boiling the solution and then by performing gravity filtration

Subscribe to view the full document.

C. A very soluble contaminant can be removed when they form crystals using gravity filtration. 6. Acetone is a useful cleaning solvent because it is very polar and can dissolve almost any molecule. It would not be a good recrystallization solvent because it will keep the compounds dissolved, preventing crystallization of the compound. Acetone is extremely flammable, so it can cause a fire in the lab if not used carefully.
• Fall '13
• JeramyBaum

What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern