CHE 201 Lecture Notes - Lecture 8: Boiling Chip, Boiling Point, Miscibility

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coralwhale510

7 Oct 2018

School

University at Buffalo

Department

Chemistry

Course

CHE 201

Professor

Susan Bratcher

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Document Summary

In this experiment, we will purify an unknown organic using simple microscale distillation and identification using boiling point and density measurements. After finding the measurements, we compare it to our knowns, acetone and hexane, to determine which identity is our unknown. We found out that our unknown was acetone based on the similarities between the boiling point range and density values. Then we do the solubility test to test whether the unknown is soluble in water or not, which our unknown was not, leading to the conclusion that acetone was our unknown. Distillation is used for purification and identification of organic liquids. It is a physical process used to separate chemicals from a mixture by measuring how easily they vaporize. The vapor passes the condenser and turns into a liquid, and is able to collect. The other components of the mixture remain in the flask until most of the volatile substance boils off.

Related Questions

Note: Respond to all questions from part A to B. Thank you

A. Write a description of explanatory of this lab(write in details as much as you can)

B. Why you are doing this experiment and What you will learn in the process

Can someone please help me figure this out? We have to figure out an experiment to get at least 90% yield of compound B.

These are the topics covered that we can use to plan this experiment:

1) Basic Operations: Using a weighing balance; Separation, Density.
2)Separating the Components of Panacetin - Acid-Base Reactions, Stoichiometry Techniques: Separation, extractions
3) Identifying the Constituents of Panacetin: Key techniques: Recrystallization and Melting point
4)Synthesis of Salicylic acid . Key techniques: Reflux, Recrystallization, Melting point
5) Separation of Unknown by Chromatography-Concepts: Polarity, capillary action, Technique: Column and Thin layer chromatography
6)Dehydration of cyclohexanol to an cycloalkene. Key Concepts: Preparation, and Reactions Hydration, Halogenation & Hydro halogenation of Alkenes;
7)Polarimetric Analysis of Unknown Sugars. Key concepts: Stereochemistry Techniques: Optical rotation
8)Properties of organic compounds -Concepts: Solubility, Hydrogen bonding; Technique: Distillation
9)Preparation of 2-chloro-2-methylbutaneâAn Sn1 reaction - Key concepts: Nucleophilic Substitution reactions

How to create a table of reagents with the information given. Ester of choice is isoamyl acetate

7. SYNTHISIS OF FRUITY ESTERS USING THE FISCHER ESTERIFICATION REACTION H2504 (cat) soamyl alel acetic acie H-S04 (cat) n-butanolaccid H2504 (cat) the chemistry of fragrances, chemical equilibria Experimental techniqees: Microscale reflux, NMR, microscale aqueous extraction Adapted from: Palleros, P. K etal "Microscale Organic Laboratory". p. 480. Befone he lab period pick one of the esters drawn ahove. If you work in a team, try to coordinate this with your teammate befosehand. If you don't do this in time for the lab, then just worry about it when you get to lab, and then copy(and double-check) the rclevant dataãquestions 3a and 3b) for the ester you decide to make with your partner 2. Prepare your pre-experiment notcbook entry (lowchart, table of reagents with physical constamts, etc) 3. Answer the following questions: For only the ester you are making, please draw a dctailed clectron-pushing mechanism to show the formation of compound. There are many sesources available to you on the web, etc) fr the mechamism of the Fischer esterification reaction a. b. You will start with 500 mg of one of your starting alcohel(whichever one you will be using to gencrate your product). While the acohols are liquids, we will measure them by mass directly on the balance, no by volume (ie. the density of the alcohol will not be used: pretend the alcohol is a solid). Acetic acid (or propionic acid) will be mcasured by volume. Delermine the volume of acetic acid (or propionic acid) to add that will correspond to 40 molar equivalents based on mmols of starting c. Considering that the reaction produces water in the mechanism (question a), what reagents could be added to the reaction mixture to enhance coeversion to product? (Think of a specific Reaction Inlo 10 ml RBF, add the aleohol you chose (500 mg), acetie acid or peopionie acid (alulated quantity, by pluringe, and cone, sulfuric acid (3äº ops, no more). Do not spill conc, sulfuric acid on yourself! 2. Altach (screw on) a microscale condenser (with rubber O-ring seall) to the RBF, and flow water through You can the bottom of the condenser. Be very careful when tuming the water on to avoid a waler spill then directly clamp the condenser and have the RBF suspended it into the sand bath Heat the reaction mixture in a sand bath to a gentle boil (roughly-130-140â, but it varies for each experiment) for 45 min, and them allow the mixture to cool to necarly ambient temperature 3. Workup and purification Transfer the reaction mixture by pipette from the RBF to a 4 ml conical vial 5. Rinse the residual reaction misture from the RBF to the cotical vial using 2 ml 5% NaHCO/19% NaCl 6. Cap the tube and invert it several times to mix the layers. Vent the tube as necessary, Allow the layers 7. Wash the product with additional 5% NaHCO,19% NaCI

CHE 201 Lecture Notes - Lecture 8: Boiling Chip, Boiling Point, Miscibility

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